Find reference is a very useful functionality. Much better then the builtin dev studio.
It would be very nice to open a new find references window if Ctrl (or any other key for that manner) is pressed. Sometimes you need to open multiple window and doing it through the menu and mouse clicks is not as easy.
Sounds workable. The clone window always open up in a floater window. Can I suggest to use the same docking state as the last opened reference windows?
You can also set a keyboard shortcut to dock the active window in VS2010:
Windows -> Dock
If you want to use one shortcut, you can write a simple macro to do these commands or you can record a short macro with these commands and then assign a shortcut to it.