If you wish you update your licence type you can do so from within your customer dashboard by logging into the AppThemes homepage. You pay only the difference between licence types..
I believe it is no longer available but the theme can work with Wordpress MU as it is just the same theme.
Please help our moderating team work more efficiently by not sending us support questions via PM. You can read more about how AppThemes support works here. However, you can send a PM to follow up and remind me if I missed your support request/thread.
