I'm halfway through the mission (1.3) right now, just dropped off Kostya with the doctor, and about to kick off act II of the mission.
I haven't run into any script errors, especially around the crate bit. I did find out however you can run left, right, and backwards at full speed without dropping a crate, but I don't think you need to be too concerned about that (it's still slower than running forwards)
A suggestion would be if you can lock all vehicles except for Piotr's car - it's really the only vehicle Piotr realistically should be able to access anyway, plus you can run into a few waypointing errors if he's in the wrong vehicle at the wrong time. For example, I was able to take Kostya's car from the hut and drive it a little way - it bugged out slightly and afterwards gave me a 'mount' waypoint that only went away after I re-mounted Kostya's car, which I had left back at the hut. Olaf's car was also drivable, and that helped getting back, but both instances were out of the scope of the mission.
Another suggestion would be for the conversation you have in the car when driving to J's place should only be triggered if you're in the right vehicle - the conversation with my passengers played while I was in Kostya's car and my passengers were still sitting in my stationary hatchback back at the hut. maybe make it so the trigger that starts the conversation can only be triggered by Piotr's car. Placing [piotr's car name] in thislist
in the init of the trigger should work.
other than that though, on the technical side of the mission I can't see anything wrong so far.
but a few more grammar niggles (sorry!)
carrying the crates:
"what a slavery!" -> "what slavery!" (the 'a' is redundant)
Jegorow remarking to the head mafia guy when they all arrive:
"[pigs at gunthers'] make disappear bodies" -> "[pigs at gunthers'] make their bodies disappear"
Kostya int.:
"We have still owed him a favor" -> "We have owed him a favor" (the 'still' is present tense, but the rest of the sentence is past tense, hence the 'still' is removed)
Doctor cutscene:
[gate scene]"friend was shot down" -> "Friend was shot"
[olaf hiding car dialogue] "I'm gonna do it then..." -> "I'll do that, then..." (past tense)
[bed scene] "may he really stay" -> "can he really stay"
there is this phrase as well;
[car scene] "I admired... so consequent and determined"
I'm not sure what you're trying to say here, but the word doesn't make sense - what other synonyms could you use for what you're trying to describe?
I'll keep plugging at it when I can, including a few runthroughs just to be sure everything's alright.