... and there didn't seem to be enough dials/knobs for 3 pickups...
Well, no offence to whoever draws Mylene, but I suspect he/she has little or no knowledge of guitar construction. You might have to be a bit creative to make your bass work properly. Maybe use concentric pots so you have two knobs in the place of one?
One other question, why doesn't there seem to be the same variety of bass pickups as guitar pickups? (Lower sales?)
Well, there are quite a few different bass pickups available - look at Seymour Duncan's site for example.
Again, no offence - this time to bass players - but (with exceptions) it's not a lead instrument, it doesn't need to cut through a sound mix like guitar does. And I don't think there's so much scope/necessity for tinkering with a bass tone, you don't really need different basses for different musical styles. James Jamerson played a Precision, so does Steve Harris. It's just... bass.
Don't shoot me, bassists...