You're right, we're not driving: we're sailing into territory that looks vaguely familiar but drastically different :-D

El Fuego:

• I can agree with that. Always spend a Hero Point for any Shaping, but Major Shapings will either create a fire-based Consequence or adds a Danger Point to the pool. 
  • Just a thought, but do you want to remove the note about adding a second Danger Point? I think it may lead to some crunching players to want to save their own points, which may lead to a bit of a headache or bad feelings around the table.
  • Additional thought: Some of the major shapings just BEG to have their own consequences. Perhaps have a sample with each one?
• When you can, add the timelines for these effects. Some of them are fit for a scene (Fireflies), while others can last much longer (Firebird).
• Reading it again, I do have to ask: why the differences in flame levels between the Minor and Major shapings? If a hero has enough Hero Points, they can just use Feed to raise it to that level, so why bother with it? Sure, some of what you list as Major Shapings need larger flames, so perhaps list them on each? Maybe allow anything the size of a campfire or larger to be used, but it is exstinguished afterward?
  Example 1: Firebird would need a large flame like a bonfire, while Fireflies would need the size of a campfire at least.
  Example 2: Any fire the size of a campfire can be used, but that fire is immediately exstinguished to give life to the Shaping (which, of course, can cause more fire).
• Let's talk about individual shapings, now:
  • Firebird: I'd suggest pulling a page from Porte and state that you may bring other characters along, but each one takes a Hero Point. I'd also note the distances (it was 50 miles per day per rank; maybe midline is at 150 miles a day?). I do like that it's more of a transport power than an attack power (as the original worked like your flame serpent).
  • Flame Serpent: I think noting that water can destroy the serpent may be a good thing to note, just in case someone has a way of making it suddenly rain (especially with your Laerdom hack).
  • Sweltering Heat and Cry of the Sun: I'm really not sure I like removing dice from the pool, as that reduces multiple potential raises and the ability to gain more Hero Points. I don't think we have anything that reduces dice yet, and it does start to promote a zero-sum game. Perhaps use what we already have in existence by forcing the characters to spend additional raises.
    • Cry of the Sun: The target is blinded and must spend an additional raise on their next action.
    • Sweltering Heat: Anyone in the same vicinity (same room or similar area) must spend an additional raise on every action spent until the effect wears off or they leave the area.
  • Devour Flame: I'm not sure what you mean by "To the last flesh wound." Do you mean the flesh would prior to the Dramatic Wound that is healed, or do you mean all Flesh Wounds?
  • Heart of the Inferno: I honestly can say I really don't like this. The character takes multiple dramatic wounds, everyone around them takes 1 dramatic wound, and all this for dealing 2 extra wounds? No sir, I don't like it.
    I know you don't want to scrap it to maintain balance, so you'll either want a different power or to make it worthwhile, such as dealing a dramatic wound per hit (which might make it TOO powerful, but not too bad considering the wound hit).
  • Exstinguish: I don't like it reducing the danger pool, honestly. Again, smacks of the mechanic in Marvel (which works there, not so much here), and it makes it too much of a "Hey, let's screw with each other!" I'd toss it and leave it with just the fire removal.
  • Feed: I like the idea of enhancing the flames, but I do miss the idea of being able to keep a flame alive without proper fuel (even if it takes wounds)
    • Granted, Shining Lantern kind of does this, but it's pretty limited.
  • Ignite Passion: This is pretty neat, but doesn't have a mechanical benefit. Perhaps imply that the character is automatically Pressured to act in accordance to their strongest emotion for the scene? This way, it's got a one up on standard pressure (as you need flame and it's a magical effect), and you still get the narration going.
  • Leap of the Firebird: I'm on the fence here. I like it, but it's a bit quirky and super-powery (and not entirely fitting with the rest of the powers). 
• One thing I'm iffy about: this power automatically makes one immune to flames without any cost. Perhaps ditch Leap of the Firebird and replace it with "Flame Immunity"? Sure, it's a step away from the original, but it's a bit more balanced with everything else.

Laerdom

• To quote directly from the first edition: "Most apprentices use paper and ink to invoke the words, although they could also be written in the sand, on wood or glass, or on any other surface." It's really just the act of drawing the symbol and speaking it to invoke the power. I'd stand by writing/drawing it on anything with anything you can, because anything more permanent gets into Inscribe territory.
• I'm really torn for length of time. Most abilities from other sorceries are only there for a single action (Minor abilities in Glamour are one action), while others last much longer. 
  Just as something to try, perhaps 1 Roll/Round for the Invoke power, and one Scene was activating an Inscribe power? This way, it is comparable to both Knights of Avalon and Sorte, as most Minor powers often last for one round, and the Major can last for an entire scene?
  This also allows Inscribe to be a bit better than a Signature Weapon, but comes with an obvious cost (sorcery+days of work+limited number of runes)
• Glad we can agree with 3 runes per purchase.
• In the first edition, a sorcerer had to choose between Weather or Emotion, and could not choose both. I still like that standing, because it can show focus and also proves that not every sorcerer will be the same (as they can have a mix and match of their runes).
• Now, for the runes themselves:
  • Bevelgese: Your wording here is odd. Do you mean "comprehend" as in the Empathy skill, or do you mean to understand a language? If it's the former, blatantly state it, but if it's the latter, we don't really have anything for that in this game, and it may be an unused rune.
  • Varsel: You should note that Kjot cancels this effect.
  • Stryke: I'm a bit worried about this one. A part of me thinks it's great, but depending on how long the rune lasts, it's pretty powerful. I mean, even if it only lasts for one Round, that is still one extra damage EVERY TIME you hit something. I did the math with a friend, and a killer combo of Duelist (Ambrogia), Fencer, and Legendary Trait (Finesse) gives a crunched character 1 Raise and 10 dice at the start of the game. This means this character deals no less than 2 damage per raise (bash/feint), and can deal up to 5 (Feint+Stryke+Weaponry 3) with a Slash. That's an automatic Dramatic wound against most enemies. Might be a bit overkill.
    As an alternative, perhaps use this as a bonus die to combat, and change Kreig to a re-roll of combat dice?
  • Stans: The current weather effect is fine. For an emotional effect, how does this sound:
    "Gain two dice when attempting to calm others." From a social standpoint, if your Vendel is trying to smooth over things at a ball, it's a great effect.
  • Storsaed: I think moving this closer to the Mad Luck or using the Blessing function from Sorte would be the better bet, but give a flat bonus instead of basing it off of ranks of lashes. Like "You may grant anyone nearby that can see and hear you 3 bonus dice. They may be used on any risk until the end of the scene, but are gone once used." It feels more accurate to the original, which inspires Greatness, not normal luck.
  • Host: This is just. . .odd. The original was based on granting XP for reducing the skill. Why not pull a page from Legendary Trait: "Choose a skill. Before rolling that skill, you/the target remove one die from the pool. It is automatically a 10. If your 10s would explode, then this also explodes."
    Alternatively, you could just grant the Exploding 10s option, as it is a harvest.
  • Kreig: As I mentioned under Stryke, change this to an option to re-roll dice used in a combat situation. Give it a base number, like 3, and watch as things change.
    Having a skill of 3 only grants a one die re-roll, and some other powers can gain up to 5 re-rolled dice, so 3 seems like an okay baseline. Alternative option would be to re-roll a number of dice equal to the combat skill used, but I'm not certain if that would work well.
  • Nod: The weather effect side is great. As for the emotional side, how about:
    "Gain two dice when attempting to incite another's wrath or anger."
  • Herje: Again, not too keen on the dice removal. Perhaps set it that the target is considered to be Pressured when taking action against the one targeted by the rune (i.e. if I target the Strega with it and someone shoots her, they must spend two raises).
    Also, why do they have to say a name afterward? I didn't see anything about that in the original material, so I'm a bit confused.
  • Reise: Why not just call this a Notice roll and leave it there? Notice takes care of Perception, after all, so. . .
  • Villskap: I'm not certain on this. A part of me wants to like it, but it touched on Sanderis a bit, only without the instant kill. There's also the note in the book about the Vendel ships having mastheads that can fire lightning, which just screams to be a Villskap rune.
    Personally, I'd change it to allow a one-time attack using a lightning bolt that appears from your hands/Inscribed weapon. Treat this like a firearm (1 automatic dramatic wound), and it should be good.
    It may need some way to have a "cooldown" afterward, though. Might need to implement a number of runes able to be used each round or scene. . .
• Side note: have you considered finding a way to factor in the Become option? A part of me wants to set it up as a reward for a 5+ part story after all of the runes have been mastered, and allow a player to permanently gain the bonus of that rune without a Hero Point. Just a thought.

Sorry for the longer post, jus wanted to get all of the ideas out there before I (potentially) vanish for a few days.

Oh, I'm in agreement that I want to see something along the lines of the original sorcery return, I was just throwing out some potential, previously-existing ways to model certain effects within the existing ruleset, or to use for guidelines with designing the sorcery.

The Seidr Advantage is a fun alternative (for now), especially with the ability to permanently change Reputations for characters, but I'm really interested to see Laerdom work within the new mechanics.