Yes it screws off of the tripod. I don't know what the size is but it's too large to fit on another desktop tripod that I have. It does, however, fit on my microphone stand that you would put on the floor/stage.
Yes, if you have the appropriate software/application that can do that for you. There are a variety of text to speech applications out there, it is just a matter of finding one that works for you and your needs.