[Zubersoft]

With a large library, if I put every custom field under a drop down, it would become really difficult to use. You'd have to scroll through a ton of entries to find the one you want, instead of quickly typing the word. For a smaller library with fewer custom field entries, I could see why you want it though.

There is no way to add USB support. Google did not expose a way to transfer data from a PC to an android device over USB except through methods that require a rooted tablet using adb.

Mike