As of 6/9/2010 the best place to start is creating a "mood board" for the theme you want to create. We don't yet know how the new Virb will work. Once we have the theme documentation we'll proceed with layout.
No, not usually. For right now if you don't have the time to invest in coding it into css/html that's fine, I can help with that. May add a little "Markup by Matt Johnson" in the credits.
ABSOLUTELY! I will be sure that people know EXACTLY who designed the theme. Afterall, it's the only real payment you'll get for the free themes.
No. Virb, Virb.com, Virb's logo are all copyright of Virb Inc.
If you're interested, email me at matt@virbdesigns.com