One thing that would help assembling styles out of bits of other styles would be a 'groove extractor' like they have on a lot of MIDI DAW's (and audio, now).

Basically, this would allow you to impose the 'groove' (swing factor, 'feel', whatever you want to call it) from one part (whichever feels best to you), and impose its' feel onto other tracks you import. This would vastly increase the number of style possibilities, IMO...

BTW, anybody miss the old 'swing' knob from the earliest, simplest drum boxes and Rhythm Aces? You could get quite a lot of variety from ONE simple pattern with those...