First of all, zircon's post pretty much nails it
As for scripting, it all depends on the development team you're working with and on each specific project's needs, but I'd say that implementing game-specific audio behaviour should mainly stay in the programmers' hands. It can be as simple as a single "Play" call (like triggering an SFX), and it can be as complex as a whole code file (dynamic music that evolves along with the gameplay, for example). You can learn how to code if you like, no one's gonna stop you but I don't think that it's that useful for someone who's mainly into composing. If you do want to learn it though just let me know and I'll see if I can help you with that. I'm told audio programmers are in high demand in the game industry, but if you're not already a programmer then getting ready for such a job is definitely a few years of learning and practice, unfortunately.
That being said, I think that you can probably find some work as a freelance composer mainly with indies, but the problems in this case are that indies tend to have little budget, and finding a team in need of a composer/soundtrack is difficult. If you can't manage to find a stable job as a sound designer for an established game company though, I think composing for indies is your best bet. Spread the word, make sure people know that you want to make game music, and opportunities might just show up