I'm running Win 7, have 8 gigs of ram and Vegas is only seeing 1G available for dynamic ram preview. Does anyone know if 10 is 64-bit? If it is, how do I get it to see my ram?

FWIW, don't worry about the dynamic ram preview setting. I don't fully understand exactly what the advantages are to having more allocated to that purpose, but in my case when I set that value too high my performance went way down during rendering. When I looked at the performance data I noticed my page faults were extremely high, it appears that any RAM allocated to dynamic ram preview did not get used in the rendering process, so it was swapping to disk constantly while using less RAM for the rendering. When I reduced the dynamic ram setting back to the default amount the performance returned back to normal. Sorry I can't give you a more technical explanation, but in my experience the actual ram used for rendering appeared to be your total ram MINUS the dynamic ram preview amount, so having less allocated to that purpose is actually better than having more.

Does this program utilise the GPU when processing video as well as VRAM ??

Having a 1GB Nvidia GTX295 it seems to be working fine.