The class wouldn't matter at all. I'd save the 9 traits/all jewelry traits researched, all the motifs that I spent tens of thousands, if not hundreds of thousands of gold on, all recipes, all crafting maxed, with all riding skills maxed character. The very first one I made back at early access. Way back then I picked a dk and went with stamina, if that works for your list.
My first character was a Nord tank sDK. She became my crafter. Then realized I didn't like the Stam playstyle so I made other characters, but kept her as my crafter (invested in motifs, lots of sky shard farming and trait research). Eventually I changed her race to dunmer and made her an mDK. It's so much more tolerable to do content now, but mDK has been one of the worst performing classes in many of the balancing phases.
I'd have to keep her, even though she kinda sucks sometimes, and I find the other mag classes more fun to play.
I'd agree with the crowd and save my crafter who happens to be a Dragon Knight. My 1st character, I didn't know any better 4 + years ago . I started him as a stamina build but later converted him to a magic user, so I could easily go bad and forth with whatever meta, magic or stamina meta works best.
"We have found a cave, but I don't think there are warm fires and friendly faces inside."
No research. No fishing. Only 66 days of mount training. Extremely few skill points I can't even do daily writs at max level despite being 50 in everything but JC. And since it is a hybrid, can't do squat in this game.
So why save this one? I'd leave the game the next day, saving everyone the headache of "playing" this grindfest.
It's 2018. Isn't it time to retire this bull[censored] thing called "RNG".
Too many alts to choose from but then again there's not really a choice for me. Just like most people I don't want to loose all my motifs and furnishing plans so I would have to save my stamblade crafter. It also was the first character I made but I had to accept that I simply can't play nightblade. Tried to learn it many times but never managed to make decent damage and now I don't care anymore.
I'd rather keep DK main, but my Templar is the 9-trait (even jewelry) with all motifs and recipes known, so that's the one I'd have to keep. And I would be bitter about its performance as anything other than a healbot.
Battle not with monsters, lest ye become a monster, and if you gaze into the abyss, the abyss gazes also into you. ~Friedrich Nietzsche
Tough call, but if I'm keeping all the oufit unlocks anyways, then I'm going with my main over my crafter. I would need to research some things, but I also wouldn't exactly be starting from scratch.
When you consider the average main/crafter will have (as i do)...
All skill points (except morrowind new character)
All skills and lines levelled
All recipes
All furnishing plans
All styles
All traits
Completed all dark anchors
Completed all public dungeons and delves
Completed all group dungrons
Completed Vma
Tamriel/cyrodiil wide eploration
Cyrodiil levels
Completed main quest lines including cadwells gold and silver
Dungeon and trials achievements
Can perform all roles adequately with stat/cp/gear/skillswap
At that point imo class doesn't matter. The investment in that character is priceless
Don't see a health tank on the list but even though I like playing with that Imperial DK I would sacrifice it as I have an Argonian StamDK ready to roll.
As others have said, class is irrelevant. I would save my first character, who is my crafter, because doing otherwise would be some sort of epic stupid.
My stamblade is my first toon and also has all my crafting done. If I could only save one, it would be that toon for sure. Admittedly, she would probably find herself race changed with a staff in her hand pretty quickly, until I could power level a new mageblade (so you know, like 2-3 days tops). Haha.