I did read the books before the movies, and would have to say I pictured them to be similar to the actors/actresses in the movies. They were not dead ringers for them, but they came pretty close to being so. Elijah Wood, even though I love his acting, wasn't my Frodo. Viggo, in my minds eye, was my Strider, but as someone said he could have looked a little more weatherbeaten, and I always pictured my Strider to be a bit more well built; not that Viggo isn't. The elves, however, were perfect for me, all of them were; especially Galadriel.
I'm usually one of them that tends to have problems with my mental images being marred by the movie ones, but if anything, the movies HELPED my mental images; with the exception of Frodo, Faramir and Denethor, even though I love both Elijah and David. My mental images of them are actually similar to
Pitchwife's.
In regards to question five, I do a little of all three.
Well, more so RPGs than the other two. I truly am afraid to even ATTEMPT to write a fan-fic for Lord of the Rings; I feel that if I do so, I would only end up making a disgrace of myself. My writing is no where NEAR on par with that of Tolkien or any other seasoned writer. I have not yet attempted at drawing any of the characters or landscapes YET, because I usually need something to look at; I'm more of a cartoonist.
So I have yet to attempt at drawing them. I usually tend to only like doing very descriptive RPGs so yes, RPing tends to draw upon the mental images quite alot.