For what you've mentioned that you want to write, I'll have to chalk up another point for FruityLoops. I've got no experience, whatsoever, with creating techno/trance/beats/what have you, and even I found the program relatively intuitive and not very frustrating.
If you're looking to diverge into non-looped music (ie: composing stuff, or organizing stuff you've recorded), there are other programs I can think of that'd fit the bill better than FL Studio, but we'll cross that bridge when and if we get to it.