The game descriptions states (and thus, someone at CCP states) that "the Commando is the ultimate suppression fighter." However, aside from the two light weapons and reload bonus, nothing about the commando encourages suppression. So why not fix that? You can do so through two steps.

1. Suppression fighter implies that you are fighting within large crowds (after all, if you're suppressing then other people need to be killing). Within large crowds, the key to survival is regeneration tanking, as opposed to brick tanking which is the key for one-on-one situations. However, currently the Commando has the weakest regenerative abilities of all dropsuits in the game (what blasphemy!). A dismal 10 hp/s shield recharge rate, and no low slots for armor repping at standard and only 1 low slot at advanced and prototype. This must be changed. I'm not sure what the new values should be, that is for CCP to decide, but the shield recharge rate should be one of the better ones among dropsuits and there should either be more low slots for armor repairing or simply give the Commando a nice inherent armor repair rate. In order to do this, you would likely have to reduce the Commando's overall eHP, which would be an acceptable exchange. Now the Commando can survive as a suppression fighter.

2. As much as I like the sound of Commando's getting extra damage to specific type of weaponry, this is not in line with being the ultimate suppression fighter. Instead, give the Commando a set of racial bonuses that increase your total ammo capacity. Make it large, so at prototype you have double or even triple the normal ammo capacity (that is, 20% ammo capacity of specific weapons per level or 40% ammo capacity of specific weapons per level). I know this sounds extreme compared to the normal ammo capacity skills of 5% per level, but keep in mind those skills are for all players to give them a little more staying power, while this Commando bonus will be exclusive to the Commando and aimed at giving him suppression power. Now the Commando can actually provide suppression instead of trying to conserve their ammo for shots that hit on target because of how little ammo you get. And in actuality, this should probably be the Role Bonus for Commandos and apply to all weaponry, while the reload speed bonus should be the set of racial bonuses and only apply to specific weapons.



Now the Commando has a clearly defined role on the battlefield and stats that back it up.


TL;DR
1) More regen ability, less brick tanking
2) Swap damage bonus for generous ammo capacity bonus