Using gelled lights is okay for the background, but don't light the cosplayer with them if the aim is to showcase the costume. The reason for this, is that cosplayers spend an awful lot of time finding the right colors for their costumes, and you don't want to ruin that effort. So if you want to use a rim, use it bare or with a more natural looking color (CTO works fine in my experience).
In general, this kind of shot is okay to showcase the costume, but the poses are way too generic IMO. Cosplay photography is not fashion photography, it's not just about the costume : it's also about the character. If you don't know the character, you should talk with the cosplayer a bit about who he's portraying, and decide on a set of traits you want the photos to reflect, then improvise from that point. If you planned the shoot beforehand, you can search for reference pictures in order to get an idea about the character's general attitude and body language.
I know studio makes it harder, but try to be creative with your angles. Cosplayers appreciate this, and your shoots will look less repetitive.
What I said about using gelled lights is less valid if you go for the 'in character' shots rather than fashion type. You can mix types in a shoot though, here's a studio shoot I did last year (twas my first studio shoot at home, so it's far from perfect, but I think it's a good example of what I like to do in a shoot) : http://www.flickr.com/photos/ashurac...7626687553207/