[8FS_Bulau]

put the F-84 folder into the enabled Mods folder
put the air ini line into the MODS /STD/COM/maddox/il-2/objects/air ini
put the buttons file v 4.2 into MODS/STD/GUI/game/

These are the things that could be responsible for a 60% CTD, and everything you've described is correct, so I can't say what has gone wrong. I've suggested everything I can think of. All I can suggest is double-check every step. If you comment out the F84F line in the air.ini, does that fix the 60% CTD?