Yes, there are Mac trojans on Limewire. Download at your own stupidity risk. People that have to ask these types of questions are more likely to become victims.
You can't really get a mac "virus", only trojans. I suppose that's trivial to the OP. Just remember, if you don't enter your password, you should be fine.
limewire crashed my brother's computer several times ( as in he had to a full wipe of his hard drive) before he decided to stop using it...ive heard different results but personally i dont think its worth risking anything
I don't think Limewire is all that likely to carry unwanted code if you download it from a good site. Unless of course the base code itself has been "infected" by the authors. Frostwire is the superior product anyway.