As a sibling post to Leadership, the other complex rule (at least in the basic rules of engagement) is suppression.
As any of the military guys can confirm, the advantage of a machine gun (or automatic rifle like the C2) is not in its actual rate of fire. For instance, the C9 (M249) actually has a lower rate of fire than the C7 (M16A2). In game terms we tend to juice the support weapons to make them more dangerous. The thing is, if you were to run into an enemy on the fly in a complex of twisting corridors, you would actually want the lighter rather than the heavier weapon. The advantage of a machine gun is its effective rate of fire and sustained rate of fire. Back in the days when some sods had bolt action rifles or semi-automatics, then the distinction between an ROF 1 weapon and ROF 2 could be easily supported. But the reality of modern warfare is that every soldier carries an automatic weapon.
My point is that the Heavy RAM Laser and Heavy Deadbolt Launcher are more than simply two weapons strapped together, and a C9 is not simply a C7 that kills twice as many bad guys. An infanteer turned engineer pointed out to me: automatic rifles are point weapons, machine guns attack an area. The 30 rounds a C2 had were simply insufficient to attack an area. A true machine gun with hundreds of rounds at the ready can lay down a spindle-shaped beaten zone, which is particularly effective in enfilade fire (attacking from the flank).
So here are some suggestions that I toss into the ring.
1) Machine gun type weapons will always autofire but with no penalty.
2) Machine gun weapons do not suppress a single row of square but rather multiple rows of squares, generally 3 or 5 wide.
3) Machine gun weapons can spread fire more effectively, only losing a die for each two or three squares between targets.
Setting aside machine guns, there are a couple of other mechanical questions.
I think we should dispense with the modifiers for the target and intervening squares.
The rules for blocked and unblocked suppression should be reworked to prevent various possible abuses.