Yeah I've been watching some of his runs he has interesting stuff on his youtube for every class, and some multiple of them(he has minion witch and plants witch for example). He's not done running everything yet though, currently only has witch, sorc(vashtra), merc grenades, huntress twister(currently still member only but should be public tomorrow or so), wyvern druid and ice shot ranger, so mostly missing monk and warrior but warrior there's other speedrunners doing a lot of runs.
His disciple of vashtra run has commentary too until like act IV where he notices he's been going so fast he might actually have a world record so he goes a bit more serious. Although this recent twister build apparently beat his own record but I think if he did a pure speedrun vashtra he might have been similar times, he fucked around a bit answering twitch chat questions and what not.
Another youtube channel that has a bunch of leveling runs is
Tuadh he does lvl 1 to tier15 instead so the videos are longer but that means you see early mapping and stuff too, granted that's gonna change.
Yes to an extent, first trial is Sekhemas which is like Sanctum with the Honor second hp bar shit, but enemies barely do any damage/you don't have to kill anything, and traps also barely do any damage so it's pretty easy(it's been nerfed I think?). Second trial is the Ultimatum based one, and then 3rd and 4th you can just choose which one you want to do so you only have to do the trap one once and it's the easiest level one.
Edit: Apparently you can do only Ultimatum now even for the early ones I'm reading, but you need to drop a spawn item for it. Basically you can do 4x Trial of Chaos if you want and never do the Sekhemas one, but you'll have to ascend later as a result. Tbh the first tier is really so easy I wouldn't bother even if you hate it, it takes like 10mins and it's really hard to fail unless you're very bad at dodging anything.