XP by itself is ok, but I don't think I ever tested it with 0.9z-5. In any case I didn't hear about problems, but it may tell nothing because only few people use it (in here). If you are not sure, try 0.9z-4-1 (0.9z-5 *is* quite different on the install part).
Can XXHiEnd stream across a network? UPnp
Now you mention it so explicitly ... maybe not. I think it depends on how the driver behaves, and if you see drivers (sound devices) listed for it within XX anyway. If you see them, I see no reason why it won't work.