I know in RealBand you can copy/paste sections you like so it is easy there (duplicating progressions).

In RB you can use 'time stretch' to stretch a note, but it won't be the same as having the note played how you wanted it. That's a tough effect to pull off sometimes.

Realtracks are regular audio tracks, so what you can do with audio you can do with realtracks .. in RB at least.
I'm not that experienced in BiaB, so hopefully someone else will chime in.

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