@ SpencerSteel
Hi and welcome to the forum.
The VIRUS TI has a lot of qualities and has become a monster synth with a lot of capabilities but also with some tricks.
So, first of all you have to see the VIRUS TI not only as a synth but also as an audiointerface (soundcard), hardware controller for softsynth and a keyboard (if you take the POLAR or KEYBOARD version).
Don't worry about FL it's a good sequencer and you don't really need a ProTools system at all to do music. The new OS version of the VIRUS is now 64-bit and WIN 7 compatible, so no real problem there. For your info OS4 is on the way so I think there will be less problems for compatibility.
To say that something is working without problems is difficult to answer then there are many factors involved. But there is a very good support center at ACCESS and they will help you out when your gear is not working properly. This is really rare to have such a good support.
So now back the the synth itself, the VIRUS TI. As a bedroom musician you need somthing compact but still with a good sound. My thought would be that you get the VIRUS TI 2 Keyboard (61 keys). The reason is that with one keyboard you have a full keyrange (61 keys) in addition to the knobs, which all other versions have. If space is really small then get a POLAR.
So, if you don't plan any other hardware keyboards/syths so with the VIRUS TI 2 KEYBOARD (61 keys) or POLAR (37 keys) are those you need
With the VIRUS you don't really need the Edirol PCR-500 controller or Lexicon U22 interface, it's already in the VIRUS. And this is nice, just a three in one piece. But it's up to you to add other devices you need or have.
The VIRUS for me is one of the best synth I every had and I won't miss it anymore. There are more than 7000 sound patches ready for the VIRUS and more at your fingers when using the VC VST plug-in for full access to sounddesign you own sound even from scratch.
I hope this was a help and good luck.
Cheers