Hey there, I got a Kemper and must say it's the best piece of gear I ever bought. Didn't think I would say that at one point but for the first time I don't see a reason to buy anything else (at least for now
To the Footswitch question: You can control it via midi, there are happy users with all kinds of different midi contollers happy with it (GCX, Behringer and so on). As long as you only want to change patches any will do...for other functions, just head over to the Kemper forums, lots of info there!
There will also be a dedicated FS but my last info was earliest Q4 2013, which is a bummer, but okey...hope it will be worth the wait!