[mlangsdorf]

I think your system is probably overcomplicated, but let's see how it works in practice:

Fighter A is a typical middle-weight boxer, on the professional circuit but nothing more than a regional champion. He has ST 13, DX 12, HT 12, Speed 6, DR 1 (Tough Skin, Crushing Only), and Boxing-14.

Under normal GURPS rules, he can throw a left-right combo by making two attacks at -4, two jabs by making two attacks at -6, or two jabs and a hook by making an All-Out Attack (Double) and turning one of the attacks into a dual weapon attack, so attacks at -4, -4, and +0. In a mirror match, he can defend against two attacks with his Parry of 10, and third attack by Dodging with a 9. (Facing only a single foe, he'd probably Retreat, but that's neither here nor there).

Under your system, he might as well as throw left-right-left combos, rolling at +0, -2, -4, and possibly even toss in some Telegraphic Attacks on the end (rolling at -2, -4). He has a 6th attack possible, but why would he even use it since it's normally at -10? There are options to get more rapid strike points, but his skill is the limiting factor.

If he were a swordsman (Broadsword-14, Shield-14) instead of a boxer, he could make four rapid strikes: sword-14, kick-12, sword-10, kick-8. Possibly he can replace the kicks with shield bashes; your system is unclear.

If he were a fire elemental with a 3d burning aura, he's going to throw alternating punches and kicks for as long as possible, even sacrificing strike damage to do so, because the aura does the damage not the punch.

There's no disincentive to not throw at least two attacks, because everyone has enough rapid strike points to so (even a second attack with a maul is only 4 RSP), and the first attack has no penalty and the second attack has only a minor penalty. And it's not clear how this system works with All-Out (Double) or Extra Attack.

Honestly, I still think system is a mess. Realistically, people who punch tend to lose against people with swords, even when the puncher gets close and personal to the swordsman. If you want a different cinematic reality, take Trained by a Master.