It seems like an easy/good way to select the empty textbox would be to have it highlight when the text tool is over it (like it does when there is text in it) this way it would not interfere with regular selecting activities and still be editable and selectable.
I think text boxes should also (at least) show up in outline mode. view > display mode > outline
It would make Inkscape much better for making document templates.
My 2p.
-C