Alright, I found out what causes the CTDs - the problem is not that much with the campaign itself, but with BMS main install and it is a little wierd. After looking through the crash logs I found other people with the same problem:
So if Falcon crashes on exit after flying the campaign, just go to your screenshots and ACMI folder and remove all files (you don’t have to delete them, just back them up somewhere).
After that I didn’t have any crashes and everything was running smooth. I also fixed some errors in save0.cam file with Monster’s Terrain Tool, then brought that .cam file to an older backup of BMS root folder with screenshot and ACMI files in it and it didn’t do any crashes! I’ll upload this fix soon, just wanted to do some editing first on the ground war - set new locations for armor and lower the number of SAMs a little bit.