[Imp]

1) More suited to scenerio design or PBEM as huge amount of work vs AI. Every nation would need another pick list well 2 actually depending on whether its the target or infiltrator.

2) Bridges in this game> firstly all can support heavy armour so if any change most tanks should not be able to use wooden ones which we shall assume are "light bridges" not wooden. Satchel charges can already destroy them though its a bit hit & miss but it should be its a specialist job. Bridges really require charges to be placed carefully on the structure to take it down, a job which takes considerable time before retiring to a safe distance & pressing the plunger.
The AI would not know the diffrence between destroy & capture for buildings etc. For PBEM set building or whatever as objective turn off your units satchel charges so he does not use them & use against the building on a turn you start stationary to it, easy enough for other player to verify can have a rule 2 used in a hex is destroyed even if isnt. If know the other player can do better with rule where by eng retires to 4 hexes away after visiting & blows.

3) Already done if set to XXX for both sides only diffrence it simulated it before arrive over the battle so thats the air you can have. Again can have own rules as in use as normal or if that side has air supperiority has flights on call rather than assigned to you. These want a quick turn around to rearm & go out so can only be used for 2 passes which must happen within 4 turns of each other