This kind of communication is certainly a welcome improvement! I think the Hawken "elite" are a valuable resource and most of us are glad to provide input.
The weapon stuff all sounds fine, nothing really different for a PC player. Choosing 2 different items with 3 charges each is fine, I rarely ran three 1-use items anyways. Not sure how the replenishes would be implemented however.
The internal changes suggest sound reasonable. I'd actually suggest bringing up the value of the basic and normal extractors to 2.5 and 5 percent, respectively. At 2% there is almost no point in taking it at all, even if they do have a history of being strong. You could also give them a separate value for EU extraction, although that would be kinda pointless as no one ever takes them for the EU extraction speed, and EU extraction speed isn't really game changing anyways...
Repair kit values look solid.
I like the idea of 4 slot "expert" internals, and the upside/downside internals. The concept is fine, but balancing them might be a challenge.
I think composite armor just need the DR cut in half for now. It might still get banned in competitive play but it wouldn't be such a strong bonus for 1 slot.
Balancing multiple DR sources could be a challenge. I think you'd want to either employ a heavy diminishing returns system, or probably better, a "highest value only" system. Like while using normal deflectors (20%dr while boosting/dodging) and composite armor (20% dr after death), just give the highest value at any one time, so while boosting you'd just get 20% dr instead of 40%. So in a vanguard turret mode + composite armor would just default to the turret mode DR value. On the downside, this would make composite armor and the armor internal somewhat pointless for someone who spends a lot of time in turret mode.
The shock turret looks cool, but without seeing it in action or having some real data, I can't say anything. Don't remove turret stomping, this would shaft some mechs that have an agonizing time dealing with deployables with their weapons.