The Dummy Twins
It's actually quite legal for DUMMY objects to have any name that you want.
This is because they're not actually "objects" in the legal sense. All they
are are place-holders, and as such, they don't have to subscribe to the
same rules that legitimate objects do. In the future, we'll have a way for
you to rename them, but for now, it certainly won't screw anything up for
you to leave them that way (you'll just have to pick them visually).
Regarding saving a project file over another one by mistake. As Martin
said, it's simple to get your overwritten file back (as long as you've got
the backup system ON, which ought to be ALWAYS).
– G