Soooo right now I guess I could grind the two existing categories some more but the difference between my PBs and sums of best are within loading time variations. Maybe I still could scrap some more time but I don't feel like it. So I'll be looking into new categories, right now A Magus! and Burn It achivements are my candidates, gotta dig deeper. I thought about killing Agathoth alone but it's probably like an any% route with a bit of alchemy on top, not very interesting speedrun wise. I'm trying to find something that would deviate as much as possible from the current categories. Got any ideas?

I think you should add new categories as long as that's fun to you. Speedruns of this game will always be a bit dull looking only at the execution. However, finding a good route can be very rewarding so having a large variety of categories just makes a lot of sense. There's really no downside to it; if you think the category is too out there, you can always put it in the miscellaneous section. Unfortunately, I haven't really played this game that much and don't know what most of the achievements even are so I can't help you there. "Burn it" might be a good one to start simply because it's the least common achievement by far.

Yeah I'm looking into it, that's the only one I found that's interesting. It's very combat heavy early game because you need to join the imperial guards and fight Antidas. With limited access to alchemy in Teron, it's gonna involve putting a good amount of points in combat skills and physical abilities, which won't be usefull later. The balance is hard to find. The rest of the route is blowing up Maadoran which is only a few requirements, but involves a lot of skill points. Then kill Meru either through the siege or sabotaging the ritual. And finaly going to the temple, awaking the god and talk to Paullus. It's probably combat free if the sabotage can be done.

Edit: my current tries involve starting as merchant to avoid the first fight as an imperial guard, then betray the consortium for the guards. Doesn't work quite as well as loremaster, you need extra checks to be accepted in the guard. Would have been nice as it allows to lower perception by 1 if you don't betray Feng. Stating as another freelance doesn't offer any additional benefit. Starting as a thief or praetor prevents joining the guards, starting as an assassin involves more combat.