So how do I increase stats gains, like I'm only getting under 1% in each stat per training?
Hard to explain in one post, but the longer you play the more you will understand.
Also, the longer you play the more effective your training sessions become, the player is very weak in the beginning. By day 30-50 (granted you train enough) you should be at 100% training power, and tension should not climb on new slaves.
Essentially, resistance value is lowered the higher the shame and lower the tension.
If the tension is too high, the resistance will only go down in small increments.
Skill level is raised most effectively through sex < titjob < blowjob.
When you train a slave, the skill level effects the animations they can use.
I'm not sure what the limit is though, because I just broke 106% skill level on a slave.