I'm no expert on styles, but I think there are Realtrack styles (where you can get the style played with all realtracks in that style for all instruments, like piano, drums, bass etc)
I do not think there is a realtrack style for every realtrack (although every realtrack may be associated with a MIDI/Realtracks combination style)

Yes, in 2011 I believe you can generate tracks with a different stryle to experiment. This, to me, is easier done in Realband (which comes with BiaB for free) as in RB you can keep generating multiple tracks of the same Realtracks, get variations, and assemble a final track you like. The erase the old and do the same thing trying any realtracks you want with 48 tracks to work with.

I know of no list of substitute realtracks, it is available in the style picker and realtrack picker window.

I do not work here, but the benefits are still awesome
Make your sound your own!