Main gripe would be that the BAR and MG have the same stats. Between magazine size, non changeable barrels and military doctrines, the BAR is not a very effective machine gun.
I'd propably not give the BAR the suppression bonus. Additionally, the help distinguish the MG42 from its counterparts, I'd give it something like an extra damage die for every 6 rolled.
Some niggly details: Did US armoured inf carry 2 BAR's ? Regular inf only received one, though many squads scrounged a second one. Likewise, it wouldnt be unusual to find a springfield marksmans rifle in the squad.
For the Jerries, its highly unlikely that there'll be two MP40's in a squad, unless one is battlefield loot. For Volksgrenadier units (might be a different unit card), odds are a lot of rifles will be replaced with stg44's (if lucky) or MP40's (most likely). Likewise, VG squads will NOT split during combat. They operate as one entity. Regular German Grenadiers definately have this capability.
For a bit of extra flavour:
Bug out! US rule: A lot of US infantrymen were fresh recruits, thrown into battle. Recruits are [insert suitable number] % cheaper to buy, but if fired upon, and the squad has not reacted yet, roll 1D6. On a roll of 1-2, the squad bugs out, and moves its full move away from the firing squad. On a 3-6 they may act normally.
Walking fire! US rule: US troops often complained about being low on ammo, when they reached the point that their German or Soviet counterparts entered battle with. Once per game, a US squad may conduct walking fire. Advancing, while unloading a steady hail of bullets. This allows you to spend both actions moving AND shooting. This fire is always considered to be in cover (if the target is already in cover, no casualties are inflicted). However, double the attack dice for suppression purposes.
Mission tactics!: German rule: German troops were generally briefed on their own objectives, as well as those of their immediate superior. German units never suffer a penalty for loosing their squad leader.
EDIT: Just to clarify, Im not trying to dump all over your post. I think its great
Im a big WW2 gaming geek though so always looking to elaborate or expand