You don’t want to land anywhere in DRC, but it doesn’t mean that you can’t overfly it. Consider it etops. As far as getting into Kigali, you can absolutely overfly the DRC and descend below 310. As a matter of fact, you have to. From the NW, you’ll probably and I would recommend the DME arc. Entebbe is your best bet for an alternate as Bujumbura is Abit dodgy and doesn’t always have fuel for non sked operations.