Make sure their motivation is no higher than normal and they will be less likely to hang around if there's danger. Also, don't be afraid to dismount the crew and crawl to a point with LOS instead of exposing the vehicle to do it.
I forget if this is still possible, but you used to be able to take a QB map, buy any particular unit(s) you wanted and place them, then save it. Fire up a QB, select that map and voila', those units are there along with what you buy.
You can play it without the mods, it just won't look as good and immersive.
Mods go in Z, correct. They are tagged and will only show up in this campaign, not all of your games.
Congratulations on completing the first step towards an awesome lifetime hobby.
Playing it again multiple times is an excellent idea, so that everything becomes second nature.
If you can add a turret to a BTR-4E, then why not add a turret with quad 125mm? If it can be done, someone will likely do it. Arcade here we come.
ArmA is not particularly unique, it's a 1st/3rd person shooter, so, yeah...
Those games aren't unique, so opening them up to modders helped sales but didn't affect the developers negatively.
If BFC opens up CM, something that no one else does is suddenly available to lots of companies who'd like to copy it and it becomes an arcade game with all the changes modders would make.
As long as they are satisfied with their revenue, I want it to remain proprietary.