Also is the option of counter battery strike or fire available against opfor?
When you do mine bsp is it bsp cost per hex or do you get a set depth range to deploy? Not used them other than on opfor side so not sure if we get something like what they do depth wise or not. If we do get something depth wise and its not per hex then the below applies. It seems steep even for .5 bsp a hex if it is per hex. Just not sure on what the intent behind it is because of the opfor stuff.
There is no counterbattery fire against OPFOR artillery because OPFOR artillery isn't a tracked unit. Note also that OPFOR doesn't have the option to commit counterbattery fire (via artillery or ASFs) against you this mission either.
BSP for minefield is always "per hex". A 3-hex long, 1-hex wide, light minefield would cost 1.5 BSP (3 hexes at 0.5 BSP each). The same sized minefield, but in medium density, would cost 3 BSP. The size minimum (and elevation requirement) is necessary to prevent having 20 separate minefields in individual hexes scattered across the entire battlefield that will slow the game movement to a crawl. Note that you can take whatever size minefields you want, as long as it's at least 3 hexes long and 1 hex wide, and you pay the requisite BSP. Want a 20x1 light minefield? Pay 10 BSP and you're fine.