It would be good to mark your points with ... numbers =)
#1 "low" damage ... yes, the damage of the first (and cheapest) attack bases heavily on your stats and the one attribute. I made it not-so-fast-progressing, but I can adjust that. I need some experience values.
#2 you should need 4 more. If you acquire Shikai, you have a powerlevel of 1, at 5 you can intentionally release Shikai.
#3 play with it ... I thought about it, but took the "you are told how to do it" approach as some things might already be confusing to people. Hence the complete stats in the wiki entry.
#4 changes of the release phrases are (currently) not possible. I will make an entire "zanpakutou"-redo option available at some point. I think for donation points, though not that many as you will have no zanpakutou abilities then for a while.
phrases might be different, changes of type/form will be resets.
#5 I hope you're content with it, I know it took me a long time to think and figure out what and how to do... merging relatively-easy-to-understand along with relatively-little-stress-for-the-server as well as easy-to-expand-later-on was not easy.
#6 it is you, the fights have not changed.