yes, you can have multiple profiles in RH, and you can open multiple instances of it at the same time as well - I have had 4 different printers running at the same time before.
The only time you may run into an issue is if you have 2 printers with identical controller boards and firmware plugged into the same USB header on the PC. The PC will get confused as to which one is which.
This can be solved easily, however, by plugging one into a different USB header - like one in back and one in front if you have front ports.
Another alternative would be to use a powered USB hub
I, personally, would also recommend going into Device Manager and setting the COM ports to something higher than the default designation for each printer connected - this prevents other devices from "stealing" the COM port.
As an example, I have my #1 SD4 set as COM 13, #2 is COM 15, and so on
SD4 #1 & #2 - Lawsy carriages, E3D v6, Rumba controller board, mirror bed plate, X motor fan, upgraded PSU & Mica bed heater
SD4 #3 - in the works ~ Folgertech FT-5, rev 1
Printit Industries Beta Tester - Horizon H1