A:AnswerThe mouse has an auto-off so no need to switch it off and the USB receiver can be left in the computer. The battery typically lasts a year or so, better than any other wireless mouse.
A:AnswerI would assume not, considering both should have came with their own connector (maybe it's possible if you're techy enough to know how to change their frequencies or whatever it is that connects them - I haven't heard of that being a thing) .... I'd recommend buying a mouse/keyboard duo that come with one connector...