what to do now?

[Butan]

WM < weapon speed

So you will always be able to spam with a fast weapon even with 100+ WPF

But, 150 WPF with a 100 weapon speed weapon is faster than a 100 WPF 100 weapon speed weapon.

Depends if you want to be faster than the fastest, or save skill points. I can see you are trying to save skill points for other stats and I confirm that it is a good idea if you gear yourself with a build-compatible weapon.

I can confirm the "diminishing return speed increase" of ATH when you wear heavier armor. With ultra-heavy gear you are almost as fast with 0 ATH than, say, 3 ATH. You should STF-test a char with the armor set you wish and compare with lighter-heavier sets (with same ATH or different values) and find the one with the footwork of your choice.

[WITCHCRAFT]

Many people say above 5 shield skill is a waste of points, but I really like it. I suggest it because you have 21 agility already. You raise your shield faster, allowing you to use extremely heavy shields with insane speed. You can also use tiny shields like the buckler and they will catch projectiles way outside of their model. The raise/recovery speed you gain from high shield skill and the fact that your shield becomes nearly invincible is worth putting a couple more points into shield, IMO.