Died once trying to do Melinda at level 25ish (made a lot of mistakes trying to escape) and another time to... I forget what tbh, think it was a T2 randboss? The rest of the deaths were me trying Athamaton

Stuff I did differently:
I picked up Ice Wall much earlier than recommended, while leaning on Acid Spray a little longer since my weapon damage skills weren't as high. This felt much safer than the many runs where I skipped Ice Wall till later. It was more reliable than Quake for dangerous situations.
The biggest one for me: TAKE TINKERS AT LEVEL 20. Don't wait for the 36 cat point!!! This lets you start stockpiling dwarven-steel materials from the T2 dungeons, invest your generics earlier, and pick up recipes (that's the most important part!). Going into Dreadfell with a couple Acid Grooves and a Grounding Strap, plus two Injectors and some Salves will make life a breeze. You have plenty of stuff to spend class points on before Higher Draconic so don't worry about taking it late.
Put points more equally into Str and Wil until 30. This let me get PES without stockpiling tons of Str gear, plus I didn't have much anyway (unlucky drops). Also lets you wear nice T3 Massive Armors, which help a lot vs attack-based enemies early game.
I didn't bother maxing Wing Buffet and Ice Claw, the benefits didn't seem worth the extra points so I left them at 4/5.
Used those extra points to get 4/5 Wyrmic Guile, mostly for breath CDs.
Took Windtouched Speed second. I figured it would combo decently well with the attack/mind speed from Prismatic Slash (it did). And the Cooldown Reduction rounds up, so taking one turn CD off the various strong %weapon skills let me spend a lot fewer turns bumping and more turns churning out big damage.
Stuff I'd do differently if I did it again:
I'd probably skip AM. Mana Clash is very nice but I barely used or noticed the other skills. The ability to use strong Arcane uniques or randarts would have been nice, plus Undead Drake might be fun since Raze seems nuts with Mindstars and Dissolve. The extra generics can go towards more tinkers, extra points in Indomitable, or spending a cat point on Survival to get Device Mastery (which is super OP with tinkers anyway)
I'd consider getting Undead Drake with the last cat point; I barely used my fifth inscription (I chose to go with Primal Infusion since it dropped). Maybe lose Ice Breath since lots of things resist cold anyway. I mentioned Raze but Vampiric Surge is probably the single best survivability cooldown (which doesn't require disengaging from combat) that Wyrmic gets.
Miscellaneous notes:
Early game is very rough no matter what you do. Acidic Spray feels lackluster early in T2s, T3 2hs or Mindstars are both pretty meh unless you're incredibly lucky with drops, and you don't really have the points yet to invest in a lot of offense. Take the T2s slow and get an item with Track on it (or get it from an escort); it helps a lot.
Once you're past T2s you start becoming godly. I was level 30 before Dreadfell and PES made a big difference, but I also got some T4 mindstars out of Ruined Dungeon and my damage went up by like 33%! The Master couldn't touch me.
Oh my god why do people dump on Breaths!? They easily crit for 800-900 damage by Prides for me, on a low CD, in a ridiculous area. On Insane you get so much loot you'll probably run into either Chromatic Harness or Mnemonic before endgame. I got both and wowza, I could spam breaths every turn until pretty much anything barring bosses was dead. High EQ means nothing during PES since you'll have like 200 Wil anyway, lol.
Bloodcaller is MVP! DEFINITELY GET IT ASAP on Wyrmic. Fights with tons of enemies go from deadly to completely trivial since you'll leech back tons of HP every turn even from just Ice Claw/Wing Buffet. Add Prismatic Slash and Breaths later and you should never start a turn under 100% HP, haha. I never took it off once I got it.
Ruthless Grip and/or a totem with Rushing Claws. Definitely keep an eye out for these, being able to close range covers a MAJOR weakness of Wyrmic through most of the game. Grip is probably better if you get some points in Device Mastery, since it also adds nice flat damage for your Dissolve and you can use it twice back-to-back.
Thanks so much for the guide. I feel like a lot of people kind of diss Wyrmic as a weak class, but it's incredibly powerful once you get past the rough early-game hump, and not dependant on OP uniques (but they do help!).