The reason for the anemic jumps is that they make puzzle desing much easier. Previously i had a stronger jump and it allowed you to cheese a lot of puzzles.
I rarely use mesh colliders in the game because of their performane implact. Only a few objects have it. And the movement and collision detection are entirely custom and doesn't use rigidbodies. A rigidbody based movement introduces lots of problems with camera jitter and world interaction when it shouldn't happen. And also i use a system where certain objects can override the player's amovement in unique ways and it would be much harder to do with rigidbodies. As for the collision detection problems: I have no idea yet what causes them, it's an investigation in progress. It must be some edge case with the capsulecast function.