I seem to recall hearing that a Cirrus landed there fine.
Yep, that would be mine. (Although I think at least one more landed there).
And yes, the club has at least officially moved to Zeljava (and they call it Aeroclub Zeljava, not Aeroclub Una anymore). Practically speaking though, I think Zeljava is not yet in any way approved as a civil airfield.
Very little GA in BIH indeed, and mostly some old gliders, tugs and a few ultralights. Airfield density is low (as in Croatia, after all).
I would not expect that to change for at least a year or two.
Could be. It could also be no issue anymore much sooner.
Welcome to EuroGA, Oscar 
I have never flown to Bosnia but done other bits of former Yugoslavia many times. It’s a beautiful destination, and Croatia and Slovenia are heaven for GA, with well organised airports and great scenery. I have some trip reports here.
