Can I use a friends Inspire 1 Pro TB48 battery on my Inspire 1 ? Is there any different firmware?

That depends on what FW version his Inspire is set to. The difference is not between Pro or V1 - V2, the FW differences are for camera only, not the aircraft. Try it in, if is says you need a FW update, it is because the aircraft itself is on a different version.

Yes you can. The Inspire 1 TB47 an TB48 are not aircraft version specific. As Aeromirage states, there are firmware upgrades, and the GO App will advise you, but they can be ignored or applied as your friend desires. Either way, it will not affect your operation.