I think you've already got a ticket open with us, but I'll put my answers up here as well in case anyone else has the same questions in future:
1. In general, change indicators let you know that an object has changes to commit. Change indicators with a white center mean that an object has been dropped from the tree - we can't put a white change indicator on the object in question, because it no longer exists.
2. We don't current have any object locking in SQL Source Control, but we're working on a few ways we might implement that. Currently, if two developers are working on an object at the same time, there's a chance of conflicts - here's an article on how SQL Source Control deals with that: http://documentation.red-gate.com/displ ... /Conflicts
3. There's a few things that could cause TFS synchronization to be slow - are you on a VPN or is it at a remote location? Do other clients connect OK? How many developers do you have connecting at once?