Tom, hey, I love your site. I mean I really love this site, but I am not going to kiss your tail and tell you these are good ideas.
I don't want to vote to change someone's score, I want to vote to give them the score that I think they deserve. This is a terrible idea because it will simply annoy many old users. The same 'goal' can be accomplished now by just using <shudder> 0's and 5's.
Also, it seems that the crowd is fairly evenly split on the issue...so why go to all of the trouble. There are many ways to freshen the site up, but don't use this one. All that work to simply LIMIT the input of the users. I would actually rather PAY to use this site than have you limit the voting. Hell, I think it would be a much better idea to INCREASE the vote choices to 10!
Sorry, I was ranting. Anyways, lets look as a community for other ways to improve things and let this go. Thanks again, bro, for a great site.