1. Yes, but not Midi soloists (unless you generate each separately and then combine in a proper midi editing software or daw/sequencer). You can have two or more midi instruments playing the soloist part via the harmonising feature, but that's not quite the same thing.
If multiple Realtrack soloists is what you want, however, then you got several ways to do it, such as picking the "Custom" option inside the "Generate and play a Solo" window, or alternatively select them like any rhythmical RT's via the "Medley" function inside the standard Realtrack Picker dialogue.

2. Easy! You go into that "Generate and play a Solo" dialogue (best place to start any soloists in my view!) and use either the "Custom" function or the "Solo which Choruses" function.

There's only one thing to do in crisis like this - Sleep on it!
----------------------------------------------------------------------
BBox 2022 Audiophile, Mac Pro Intel, OSX 10.6.8, 800x600 (TV VGA)