first answer: bass is a tricky one eh! One thing that might be worth trying is eq'ing out some of the lowest frequencies. That's right, the low ones. Try a sharp high pas filter on the bass line to take out the frequencies below about 40hz. The human ear can't really hear what's going on down there anyway and these frquencies eat up headroom and make the bassline sound 'flabby' instaed of 'fat'... By taking out these freqs you can then raise the overall volume of the bassline without it sounding too much..
I don't use FL, so I don't know what exactly that bass sound you refer to sounds like. Does it have a long decay? Sometimes, a bassline with lots of tail-end sounds great on its own, but when u add beats it kind of just 'disappears'.. By shortening the decay time the overall effect is a much tighter, punchier bassline. You can leave the original for the breakdown...Finally, compress your bassline and make sure it's a mono track - many a good bassline has been lost to the 'wonder' of stereo sound!!
second answer: compression is a black art. there is little chance that anyone one these forums will have the time or energy to fully explain it. There are, however, hundreds of good articles written by experts out there on the web, so go get 'em! You need to learn compression for yourself for it to have any real meaning. Once you master the art of compression, your tracks will come alive! Promise!!
good luck I hope I've been of some help
