when playing SK I dont like to follow specific level paths, I just kind of go where the clockworks take me. That being said, would it be better for me to mix and match armor pieces to protect from all kinds of damage, or would it still be more beneficial to put all my defense in a certain type?
armor question
ok. the armor all adds up right? so if i have a shield, helm, and armor that all have elemental defense, that would give me 3 times the amount of elemental protection as only having one piece with elemental protection, or something like that?
Blocking alone isn't enough in T3. A dozen kats shooting you at once breaks a shield pretty fast, and in 3+ parties, it's hard to avoid the phantom's triple-curse coming from two directions (less hard if you fight them where there's plenty of gravestones to duck behind, of course) and that'll shatter shields pretty well too. Plenty of dodging and strategy is needed (and I still have a terrible time in 3+ graveyards although duo and solo graveyards aren't so bad now that I've more-or-less mastered the hit-hit-shield-dodge-rinse-repeat zombie dance).
Still, I equip for normal+elemental and even if I make a set of shadow-defense armor for undead strata in the future, I can't quite see equipping it for the 1-in-3 or 1-in-4 chance of hitting a graveyard in a strata with a '?' level. OTOH, elemental is great in fire, freeze, poison, beast, jelly, etc. levels. Clear winner for general utility. :) That is, normal+elemental, of course! :O Which is to say, vog cub and/or magic set, really, when you get down to it. (With other options for bombers and gunners).
(And yes, armor is additive, but your normal/elemental defense from shield is a little different, check the wiki on shields.)
Your shield only adds to your defenses while you're blocking with it.
Also, Piercing defense sucks. Only spike traps and merged Lichens will ever hit you with it. You can live without it.
Well currently the majority of damage is "Normal", especially at the earlier floors. But the second and third most common damage types are Elemental and Shadow. You can safely ignore Shadow if you've got blocking down, so armour which gives you Normal and Elemental resistance is a good idea. Mixing and matching to acquire these is not entirely a bad idea.