How important is it to fill our the profile completely?

How important are fields like favorite music, movies, about me, interests, activities, captions for pics etc.?

The reason I ask is that it seems like a pain to have to make up interests for a ton of nonexistent people, but the one profile I made that was fully filled out has like 5 times as many friend requests coming in as the ones with less info.

I am not 100% convinced this is the reason though, cause the model in the pics is also quite a bit hotter than some of the others and she has joined a few more groups than the rest,

What do you guys think?

Depends on the kind of friends you are after. You can get a lot of friends with just some sexy pictures, but they are usually going to be pretty aware that you just a fake profile trying to get friends.

You are going to get better quality results with a complete profile. It's not just about the number of friends, but also how those friends will convert. People that think you are a real person are much more likely to do what you ask. Spend an hour making 4 or 5 complete profiles and just recycle them. Most profiles are basically the same shit anyways so no one is going to notice.