I respect the design decision to limit character growth. My only "gripe" at that point is that outside of a competition for the Highest Score, there's little reason to play after you beat the game at that point. By getting people used to gaining experience for killing enemies, and then dropping a "Relatively" low cap on it, you neuter replayability once someone's gone through the three major builds. (Which isn't a bad thing. I'm just noting it.)
That said, the game is very enjoyable while it lasts. Suggestions/Ideas in no particular order:
1) The ability to change your skill points around after you've beaten the game.
2) Tweaking the Divine Tree so that mastering it makes healing frequently more reasonable, as mastering this tree really limits your AOE capabilities.
3) Possibly a Kill % as well as a "Score" for Survival Mode (Or just Enemies let past Count).
4) Visual Changes for your Character as his rank changes.
5) Combo Ranks?
6) Don't spend too much time tweaking this game when you've got other ideas you can be fulfilling. :P
Again, I enjoyed it, and hope to see more from you in future. ^.^