How does one improve those skills not taught at the academy? Performance, stealth, and survival don't seem to have a way to "get good enough so attempting the skill allows natural growth".
Bring slaves or mercs with the Wild-Born trait and decent survival traits along with you on hunts, their survival skills will aid you.Yet hunting depends on survival and mine is 10. So if I want leather I need to successfully hunt, but hunting results suck because survival is at minimum and can't be improved save through successful hunting...
As for stealth, I think it's possible to train it picking up the Boneclaw dung in the lair, but don't quote me on that, because I'm not sure if it's only on critical rolls or what.
Point being, no reasonable method of training stealth.