Some more musings on GURPS and perks and such that are missing, and pondering on the workings of melee combat damage.
PERK: Walk the Trigger. Normally semi automatic weapons cannot be used for Spraying Fire, even if they meet the 5+ RoF through things like Fast Firing. Walk the Trigger means the shooter has practiced maintaining a fast, steady cadence of fire separately from the point of aim, allowing the gun to be used in a manner identical to that of a full auto.
PERK: Running Ready. You've practiced controlling your body. So long as you do not exceed your Long Distance move speed and the objects to be interacted with are not linked to bodyparts used for motion, you may perform a ready maneuver while moving. EXAMPLE, drawing a weapon or magazine from a quality belt holster while running is fine, doing the same from holsters lashed to your thighs is not.
PERK: Recoil compensation. Through sheer mass or special stances, you've learned to keep control of your weapon. When using the higher fire rates of Fast Firing with a semiauto gun, reduce the added recoil by 1. Cannot reduce the recoil below base value, only serves to allow more accurate high RoF shooting.
High Strength Melee Weapons
GURPS 4e is pretty clearly balanced for people within a few points of "average" ST of 10. This works well enough, unless you have a big bruiser of a character. Where a difference between a knife and a broadsword's average damage is quite significant at ST 10, it becomes almost negligible at something like ST 17. The rules for melee damage scale based on ST fairly well, and include a measure of the difference in power into the progression, but a Swing+1 sword remains Swing+1, whether it's being driven by a 1d-1 swing or a 3d swing. I can't think of anything better to replace it with that doesn't adding probably needless levels of complexity, but it still seems to need a bit of pondering.
High Skill Melee Weapon Damage
Unarmed combat in GURPS gains bonuses as your skill increases, which is good because much of combat is all in the technique. The problem I see is that to do this with weapon skills requires the Weapon Master advantage. Weapon Master damage bonuses follow the progression of Boxing and Karate, with DX+1 skill giving +1 damage/die, and DX+2 skill giving +2 damage/die. I'm inclined to house rule that high skill with a melee weapon follows the bonus progression of Brawling, with +1 dmg/die at DX+2 skill. Not a lot, but enough to represent the boost gained due to proficiency.