Only a reply to a very small bit of your question, but Parallels shared folders don't seem to be Samba or similar (ie, that part has always worked no matter how strange I've made my virtual network setup...)

For me my Mac Pro works really well; so well that I actually only turn my PC on once a month or so. I have Parallels & XP for running some work tools (ARM Realview JTAG and Cadence Allegro PCB viewer) but it turns out that I don't actually need to use a windows box as often as I thought I did.

Hugo