You can have ProSeries on multiple computers.   Install on each one the same way, then you can use BackUp/Restore within PS to move client files from one to the other on a flashdrive.

Your EFIN is only good for one location, so you should only be Efiling from one computer.   Efiling from multiple computers can make receiving acknowledgments confusing too, so doing all Efiling from the same computer seems to work best.