You can use 1 sub for ISboxer on upp to five computers

You dont need FTL macros with ISboxer

no, Innerspace is the platform you run ISboxer on(as far as i know, i dont use it for anything else hah)

the mouse repeating is fairly simple, tho ive never had good luck doing this with KC or ISboxer. you can search the forums here there are some threads on the subject