I thought I found the problem, in the init.sqf you opened a bracket at
[] spawn {
waitUntil {!(isnil "BIS_fnc_init")};
...
Which wasn't closed at the end. But even with that fixed it crashes after a little while.
Then I tried it with the init.sqf disabled, same result.
Only running ACE2 here, no SLX or other fancy stuff.
Have you tried it without ACE2 yet?
Update:
Maybe, but only maybe, I have something.
There were two triggers in the mission with the condition set to "this " - with a blank space at the end. After
fixing that I was able to play for 10 mins without crash - with still deactivated init.sqf
After enabling the init.sqf, it again crashed after a few minutes.