I like the comment and star system, although maybe I wouldn't so much if my rating were poor. If it disappeared, I would miss it a little, but I wouldn't complain.
I generally don't sign my comments, be they good or bad. I would prefer anonymous comments and votes to remain possible, for reasons partially discussed below, but again, wouldn't object if signing became mandatory.
I actually see the star system as a way to let people know they're jerks without being obnoxious about it. Instead of taking the time and going out of your way to tell them so in the forum or via PM (and very possibly starting a flame war), you can just make a few clicks and type a short message that they can heed or ignore at their leisure. If there is serious harassment going on via this system -- not that I've seen or heard of it, but if there is -- it's not worth having to put up with that.
I'm also completely oblivious to any "logrolling" or "backscratching" that may go on over votes, and think that's pretty sad (as in pathetic) if it does happen. One of the advantages of being able to vote anonymously, and one of the reasons why I do so, is that you can avoid that sort of thing.
I will say that if just anyone who walked in off the street could vote, I would regard the system as totally worthless, and would support its removal. One vote per donor seems sensible to me.
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The what mentioned above is total fiction. Please don't take it seriously!