I really appreciate you talking this out with me.
1. Alright, knowing the minutia of dice priority might not be unimportant, but since no one has to do the arbitration, you can't deny it's less important.
2. If the wielder fails to benefit too much, they are going to stop wasting their gold wearing special gear (see the Poison Dagger). Then No one benefits.
3. Conjecture perhaps, but Dice will either be attacking or defending. They'll either cancel each other, ignore each other, or you are getting into some very weird potential interactions, FAR more complex and harder to learn than dice priority.
4. Its an obvious solution because it's a good one. Some dice will want to be fast, some dice will want to be slow, other dice... well honestly I can't think of an effect that wouldn't be better served fast or slow (because you either want it to be blocked or not). In that regard maybe there's no such thing as a medium speed special dice needed. Every special dice is a special new rule to remember. If you are going to create a lot more, returning the dice speed rule will be a small addition that will ensure they are worth using.
5. No one is getting 10 shields without crazy shenanigans (a King losing a Rot battle, but then you probably have 10+hits), it's hard enough to 8+ hits. Most times attack will outnumber shield ensuring that a pierce dice will underperform a plain static hit+ even if they didn't "miss" by landing outside the block range.
6. Well, the New longbow and pistols would be bad even with priority back. Poison dagger might be passable with negative priority, but still probably under performs. Hero shield and New Chainmail aren't going to get much better with priority because nothing makes reflections happen at the end naturally. Iron pike would become as good as old longbow for attacking, which might be nice enough to bump it's cost to 3.
7. Yes, a portion, and while game development is not a democracy (it's your game) I would think if 70% of the gaming population was against or neutral to the change, and only 30% or less actually liked it, it'd be worth changing back before it got too much inertia and influenced other changes like how Longbow, Pistols, and Chainmail were.
8. Going back to Poison. Yes it "could" do 1-4 damage, but if the target dies anyway it does 0. The victim decides how much AP they want to spend, so it does the amount of damage the victim wants to receive (you might help set up a death warp). The damage becomes very healable if they have a Sap in hand, or they could cure it with Taster/Cleansing spell. Maybe rather than "poison" binary status, poison dice left "charges" on the victim that get consumed with steps, so there would actually be value in hitting with more than 1 poison die.