3. It might make more sense to move it that way. I did see the line 'I hear something... friends?', but as the first real interaction with other salvors is on the other mission, I think it would make more sense to have it appear right after.
4. I've got the wrong mission, it's the “Collapsed Machine Station” I'm talking about the big fish at the bottom of the left cavern. I couldn't catch it yesterday (I tried several ways), but I just caught it testing. I'm not sure why, but it seems difficult to catch, despite the fact that it follows the salvor. I thought it wasn't catchable at all yesterday.
6. If you want to, you don't necessarily need a fix. It's a good idea, you get screwed the first time and it forces you to redo the level carefully. You just need to make the player understand in advance that having too many Salvors following is no good.You could say to your salvor something like “Be careful not to get too many colleagues around you, they could prevent you from working properly”.
7. By adding a few lines of dialog specific to a run where NTR is avoided, I think you could calm people who get upset about it (some alternatives lines on dates for example). Instead of simply removing CGs as an option, offering “drill” type equipment to pierce barricades on doors that require several salvors could force players to play well to get through an NTR free run. It would force them to play sneaky (which could be fun). Personally, I don't mind if there's NTR, I think it could add a bit of spice and drama to the game, but offering the possibility of avoiding it if you're good and reward you for doing so would probably give the game a bonus lifespan.
I'd be happy to lend a hand on the next update if there's room :)