Kigali is an amazingly great little airport. Its efficient (not European standards) for Africa, everything is clean, tidy, and works as it should. I often operate in and out of there in a private jet, and I would not give security at the airport or in town a second thought. You won't need armed guards at the plane unless you are carrying some serious VIPs or items. Ground handling is there, albeit expensive for the services actually received. There's a courtesy bus to ferry to and from the terminal (jets get parked out in a remote parking). And everything in the terminal works well. Town is a happily chaotic busy place. Hotels are varied from good to 'good heavens', traffic is okay for the region but there can be delays. In short, its pretty much fine! No worries...