A:AnswerAbsolutely. Worked flawlessly with my 12.9 iPad Pro 2G. Though I did not connect to printers via USB - I connected to many other USB devices to include microphones, home automation controllers, headsets, mouse and keyboards without issue.
A:AnswerI haven’t done it myself, but I have plugged in numerous other usb devices and so far EVERYTHING has worked. I believe a usb mouse would be no different.