After having done some testing, here are my observations:

Enemy behavior is great, a huge improvement compared to the earlier releases.

Great to see that you have included hostage rescue missions. Some observations that could help make these missions even better:

In the savegame that you provided the prison is on one side of the map and the enemy troops are in a building on the other side. So I can just walk to the prison, blow the door, let the hostage escape and then retreat. Without any enemy contact I get the reward. Possible solution: enemy troops should be located near the prison and patrol there, making it hard even to approach the area.

If I get a hostage rescue mission I can wait (on the strategic map) for allies to weaken the enemy troops. When the enemies are almost eliminated I join the battle. The battle is won easily and I get the reward. Maybe it would be better to get the award only if a player is really taking part of that mission.

When the alarm sounds, enemies don't really seem to head for the prison in order to kill the hostages. Actually in all the hostage rescue missions that I have played (normal and hard) never any enemy tried to get close to the prison. I think they could be more determined to do so.

After finishing a hostage quest successfully, sometimes the popup which tells you where to go for the reward does not appear. However it appears when you drive to another city and then drive back to the city where the hostage was rescued. Same bug occurs sometimes, when you drive to collect the reward. Sometimes you have to enter the city several times until the reward pops up.

Weapon balance: I think grenades and especially the grenade launcher have a very high range, damage an accuracy. Considering the explosion radius the grenade launcher has a range comparable to the FAL sniper rifle. Other weapons fall short. Maybe assault rifles and snipers should have higher firing range to compensate the advantage of nades.

As you already have included hostage rescue missions: what about turning it the other way around? In assassination missions the player does not have to rescue a hostage but he has to enter a building and kill the enemy leader. Mission is over when this goal is achieved, remaining enemies surrender. That would be an interesting change to the normal kill-everybody missions.

I hope You will keep up with this project. I will definitely come back to do some testing in one of the next releases.

Hey Ed, nice to see that development is going on. I could do some testing but at the moment I do not have the time to play a full campaign. Could you provide some save game files of situations that are important to be tested? For example if you consider hostage rescue missions an important subject for testing you could provide some save game files of a campaign at exactly this point and with a specific weapon layout.