The only real challenge, I think, is finding the role you need to play in a certain game - is it really useful to play as BA the way things are going in the match, etc.
Yeah, a lot of it is map-dependent. On cooler maps or maps with water, mechs that usually run really hot and are coolant-dependent become better choices. It seems that only on the very hottest maps are flamer-dedicated attacks remotely useful. BA is insanely useful if you start to see a lot of Demolishers/Morrigus/LongToms/Arrows/LRMs, or even assault mechs. Some otherwise-good mechs are very bad against BA. The problem is the barrier of entry for BA is pretty high; you'll die a lot before you're useful. Errodien is the best BA player out there, with Coffin and Strik3r and maybe me after. But I still have a lot of trouble sometimes.
But I know your question wasn't specific to BA. If it's a points game, you have a lot more flexibility in what you choose because of the points multiplier. In Terrain Control (tickets), you should choose an asset that is fast to sneak bases, get something bigger and go in groups to take heavily-fortified bases (if you have to), or defend a base in something big (BORING). If it's a tickets TSA game, uh... just try not to die too many times in expensive assets.
The only BA-related thing I haven't been able to figure out yet is how do you 'ride' mechs? I have heard other players offering giving me a lift, but I can't for the life of me figure out how to grab a hold on their mech - is it just a matter of landing on top of the mech and then being carried along? There's no key or some such thing I need to press? That being said, I enjoy playing as BA - yes I die alot, I kill very few enemies, but I damage some here and others there and buzz in and out of melees between others, dodging shots (sometimes not); it's a crapload of fun.
