Nicely arrayed set of suggestions. I hope you don’t mind if I chip in some thoughts as well? I won’t comment on everything, just a few of my own thoughts after extensive experience.
And just out of curiosity; have you tried the buffs that just came out on some weapons today? Some of the dual weapons and the Great Axe got some buffs.
I think the Executioner Sword’s overhead is at an okay speed. I would give it back its stronger headshot multiplier (the nerf it just got), but the biggest buff it needs (and this is coming from someone who has used the XSword for hundreds of hours across both games), is that it needs to stagger more enemies, even if it doesn’t damage them. In VT1, it staggered every single enemy hit, though it damaged only five. This was key towards letting its relatively slow attack speed control hordes and function. Or instead, an attack speed increase on the lights would be do great to let it control groups better. I know the overhead seems utter garbo - but after using it long enough, you learn the timing for it well. With the original modifier, it was properly risk/reward; massive damage for a long windup.
I think another possible direction to go with the halberd would be to take away the armor piercing on its basic attacks. This would mean that the double overhead wouldn’t instantly eradicate Stormvermin, and you couldn’t just first attack-cancel into hordes with impunity. You’d actually have to use its charged attacks to deal with armor, then. The double-overhead could stay and could still be useful, just not nearly as useful.
Love your idea for the Kruber/Sienna Arming Sword, because frankly that third attack in the chain IS its best anti-armor attack. For Elf 1-handed sword as well - also yes, please. A faster charge on its heavy would do a lot of good.
As for the Glaive . . . I really wouldn’t want to see it nerfed into the ground. I would keep it the same as it was prior to the current patch except to lower its cleave. At least make it work more for its good armor-piercing.