Perhaps I misread your question, I do not totally get what you are trying to do.
But why not call SaveChanges() after the change and when all checks are positive perform a remove() and call savechanges() again?
There is no harm is calling SaveChanges() multiple times. It will mirror it's data to your database. If you perform a remove it will try to delete it in your database. That's the nice thing about it.. it does what you tell it to do ;-)