Thanks for the update
Balious, and glad to hear that lowering your textures helped you continuing with the game.
If I understood right, the things should be like this, and they do go like this: When you are speaking with Sid at the beginning of the game in his basement, you are asked to find an artifact as well. On the menu, the dialog comes in English and once you click on accepting the quest, the screen prompt says "Find the artifact" in English. No Russian. That prompt was like that (Russian) in version2.0 only. Have you fully cleaned your gamedata folder? (but maybe I understood the question wrong)
Please try reducing your textures a bit more, grass density: to the lowest (on 1/4 bar), distance: at least half, others, too. You'd be better off in Static Light I believe, if you haven't tried it, all that should solve your inventory apperance glitches.
About the choppers: Yes the second one that comes around Tolik's spot, that was not present in 2.4 (and below),
is hostile. And it's amazing that how lucky you are that it killed all the mutants around you while firing at you, lol. Yes, it was firing at you.
Next time hide well.
You ask: "What are the chances of a Flesh being on its own?" Well, let me answer with a question: "What are the chances are finding a 20 quit on the pavement?"
You may find them both as you wish, but when? Who knows? That's the living AI in the game.
Good gaming.