I don't use VR but I did have stutters and had some crashes. I did the slow repair and haven't had issues in the last hour or so with crashing or stutters.
I found if you bind PTT Stick to \ it will open the communication window but it also hot mic's your radio on SRS. I haven't used TACAN as I am new to the aircraft. Not sure what the issue is.
Having same issue with MB-339 after buying it earlier today. / will not open the menus nor will rebinding that to different key(s) with and without modifiers.