I have a couple of things to say....
First...Just because Yumei was nice enough to create a site for us to use for bios and whatnot does not mean he makes rules for SL. he will tell you as much for himself. I have seen it mentioned a couple of times here lately about what Yumei allows for RP...and that is just a bad assumption and needs to stop.
We decide what we want to do and what we do not want to do when it comes to rp.
Secondly...
this issue of claiming stuff has been turned inside out and upside down a million times, WE discuss what jutsu should be allowed, We discuss who should have it. We discuss how it should be nerfed or buffed. and it all comes back round to who is making the rules and if they do not fit with my personal style of rp or no.
More and more as we get into these topics I am going back to my original stance. Rules stink and you do not have the right to enforce them upon me or anyone. Even if this is like an ostritch putting its head into the sand, I do believe this. but how to avoid the problems that no rule, or too many rules create?
What if...
We made bios, listed out jutsu...like we are doing. and then ask for discussion upon them to be held. Focus on what YOU as an individual are doing instead of monitoring what someone else is doing.
Ask for the opinions of other with the stipulation that YOU have the final say on your character. in this way your creativity will not be hindered and you will be made away of how others are likely to react to certain claims you are making.
This is what Kobayashi Toshiro, whom you say had ridiculous claims, did when he was proposing some new powers for his character. It seemed to work out alright.