Let me see if I can explain this a bit better. I want to setup a fan site, but it is not completely a fan site, more like a brieft dedication to a person.... IE: My fan is John Doe... I want to setup: doeisgreat.com The site itself is not about John Doe or Mr Doe but just one section that dedicates the site to John Doe.... What if some wild card chance the site becomes famous, I do not want John Doe suing me because he is jelous or he just decides he wants the domain because it is doeisgreat.com Does John Doe even have a shot with a lawsuit? You just can not do anything these days without wondering if you are going to step on someone elses toes, and wonder if they are going to sue you for the work you have done....
Assuming you're not talking about a pure fan site that takes in no revenue whatsoever (no ads, no donations, no memberships) .... then maybe. If you are going to have a revenue motive, the answer is pretty simple..... don't use someone else's mark or name in the domain name. Don't get cute, don't try and get around it with partial names or misspellings unless you have permission. A deep pocket can outspend you in court. Very few people have a few hundred thousand to spend on keeping a domain when even if they win, they are out legal fees. Even the guy who used to own madonna.com spent a million in legal fees and still lost the domain to the singer. Had he not put content on the site related to the singer, he would still own the domain.
There are thousands upon thousands of very successful fan sites out there. I cant see a fan site being a problem. I think like mjewel says "don't use someone else's mark or name in the domain name" that would be your best bet.
I'm not a lawyer but I think you're entitled to free speech. However, you CANNOT make any revenue from it or they'll say you're make profits of the name.