Yes, Sniper is a 1.5 multiplier for CHs. So they now do 2.25x damage.
So, it seems the priority is Abilities -> Types -> Items. Such a shame.
And just to be sure: do you need to hit to activate those items? As in, if I use Thunder Shock against a +6 Snow Cloak pokémon holding a Cell Battery or with the Motor Drive ability, will I always activate it, going against all odds? And do these items "absorb" the damage, or do the pokémon still takes full damage?
It seems that as far as abilities go, they do not take into account accuracy, only move selection. For the items to work, they need to hit, but I will do a quick test:
I used the same Electivire, except gave it Flash just because that's the only move I had on hand. I gave my Talonflame the Cell Battery
Electivire v. Ampharos:
Electivire fully reduces Ampharos's Accuracy through Flash (6 stages, I believe)
After, Ampharos uses Thunderbolt, Motor Drive activates before the animation. Just to be sure, it's used 4 more times, same thing.
Absorb abilities do not depend on accuracy.
Next, I switch in my Talonflame with the Cell Battery. First hit, Thunderbolt misses, Cell Battery does not activate.
Absorb->Stat hold items require accuracy.
Second hit, Thunderbolt lands, kills Talonflame, without the Cell Battery activating.
Absorb->Stat hold items require attacks to hit, and activate after damage calculation (just to be sure I used it on an Aggron that did not die to Thunderbolt, and the Battery activated after the damage)
. So, these items do not absorb, they just give added effects.
While I myself don't believe it would be so, a question could still lie in if these items even slightly reduce the damage taken from these type attacks. My testing partner had to leave so I can't do this right now (conveniently), so I'll leave it for now. EDIT: He's back, I will now test this. Upcoming post I guess, it's for a different point?
The strange thing about this is that, as said, Sap Sipper still activates on Grass types if a powder move is used against them. So yes, as you said, Abilities take precedent over types.
Just to reiterate that observation
Priority is in the order, Abilities > Type/Other Immunities > Item Activation. I say Type/Other Immunities because the Item activations, from my research, require hits, so other immunities, namely, Ability immunities like the aspect of Motor Drive ACTUALLY not having Electric type attacks hit, will prevent these items from activating at all, since they only do so after damage calculation. Extrapolating, I can assume it is the same for all these types of items (Absorb Bulb, Snowball, Luminous Moss, Weakness Policy, etc.).