It seems unnecessarily complicated, much like the Warlock, which is far more complex than any other class. I was hoping for something more straight-forward.
You might be over-constraining your design, by limiting yourself to existing cantrips. As long as nobody else can access it, you can just give them a special class power that does level-appropriate damage, without worrying about how many times you multiply your Charisma modifier.
I agree that this class is most comparable to the Warlock but I disagree that the Warlock is by far the most complex class. I think the variant sorcerer can get away with the complexity it adds because you basically have none of the ordinary management associated with spells. The special class power idea is really interesting and I will certainly consider it!
Eruption Honing seems a little too good. First there's the 120' radius: 30' is the normal. Secondly, adding +1 means that someone could end up with a +4 weapon. So I suggest just making weapons magical and add that armour also becomes magical and somewhat resistant to the three weapon damage types, reducing damage by 3 (q.v. Heavy Armour Master).
Flash-bang also seems a little good. How about allowing a save for the blindness immediately?
Nimbus Spell should cost SPs for the push. Distant Spell should also cost SPs. In fact, all metamagic should cost SPs.
Overall, I'm not sure that the class is going to be fun to play.
Yeah, I think I agree that Eruption honing is a little over the line. I'm not sure about your solution, but I'll find a way to make it less powerful. I also think it is a little off-theme because the Arcane Artisan is supposed to be kind of agnostic about the kind of crafting you are doing, but this ability seems to explicitly be about smithing.
Flash-Bang is good, but I don't think it is so much better than the blindness/deafness spell that it is based on. I'll consider the immidiate save thing though.
Thanks for the feedback! I'd love to hear more about why you think all metamagic should cost SPs and why you're worried that the class won't be fun to play!
Not a fan of another "cantrips are my thing" caster especially one with so many obvious warlock influences.
While i find the sorcerer to be a little on the "meh" side mechanically (esp with PHB only no XGTE) i would not be wanting to replace it or variant it with even less spell options.
i think the simplest and most direct "target the problem" fix i would do for the sorc would be to provide a "ten spells 1st-5th" additional **known** spells for each origin that work like the cleric's do - they are known and dont count against your known count but cannot be changed out.
A second route might be to give each sub-class one metamagic locked in - additional - but i dislike that because it has the risk of making some "winners" for say the sub-class that get twinned free vs those who get distant free. So, its my least favorite.
I dont think the class needs or benefits from a lot of overhaul and reforming, it just needs a little more of what it does already and a few extra spells known that fit your origin theme seems like the most direct fix i can see.
Thanks for taking the time to read it! It seems to me like you like the sorcerer from the PHB as it is, and that's fine! I'm not trying to say that the PHB should have been written with this variant instead. This is an alternative who don't like the way the sorcerer plays. I personally love the Warlock, and so I've moved the sorcerer closer to them.
I got from your post that you've read a lot of "cantrips are my thing" classes and that they don't interst you. I'd love to hear more from you on this. I think people keep returning to this idea because they want a magic-themed class that plays more like a rogue than it does a wizard. What do you think their goal is, and do you think they fail to realize it? What about the cantrip casters do you feel is offputting?