How exactly does it "disrupt the use of Force of Will"?
This is Painter's Servant's ability:
As Painter's Servant comes into play, choose a color.
All cards that aren't in play, spells, and permanents are the chosen color in addition to their other colors.
It specifically says in addition to, so the blue cards are still blue. It can only aid FoW and MisD.\
Otherwise, I agree with the list except for the green blast. I highly doubt it will find a good home anywhere in vintage, since you have to be playing either GW or GB in order to not have a better answer. Awesome oddities with Vulturous Zombies aside, you don't see those decks running around much.
You could also be playing UBG or UBGw and not want to splash red as well to get your mirror cards, and so be able to play something like 3color GAT (or 3color Tyrant Oath) or even Grand Inquisitor's UBGw lists, and still have access to a blast. The more I think about it, the stronger that seems. I know that the only real red card I ran in Tyrant Oath last month was REB, so I could see just cutting the Volc altogether and playing G Response instead.