-should your weapon attribute stack with attack attribute buffs (such as holy weapon, seed of water & friends), if your weapon attribute is the same as the buffs then it gets added on there. If it's different then weapon attribute overrides buffs and toggles. If you don't have weapon attribute then toggles override buffs. Max attribute from stones is 150, you can go over 150 with buffs and toggles.
-defense just stacks, you can get attribute defense from stones for a max total of 30 defense/armor piece, as well as various buffs or toggles.
regarding damage dealt, here's the testing of a nuker with various attribute lvls on their wpn vs a target with various attribute defense lvls.
-you have between 0 and 49 more p.atk than your target has defense at which point ur damage increases in increments from 0% more to 40% (if you have less than he has defense nothing happens)
-you have between 50 and 149 more p.atk than your target has defense (at which point you deal ~40% more damage than when you have 0). Damage remains constant within this range here.
-you have more than 150 element p.atk than your target has defense (at which point you deal ~70% more damage than when you have 0)
so if we're thinking it over a bit, since nukers got ~170 ele p.atk (weapon + nuke), unless you plan to max out the whole 170 and get 170 p.def to fully negate the attribute, there's no point in getting the resist beyond 30 as they'll still go +40% damage on you regardless.
note that the nuke elemental damage is by default at 20 p.atk, even starting from lower lvls, you can negate up to 10% of their damage via various resists unless they have attributes.
also, if you'd stack all resists and go beyond their p.atk which is highly unlikely at higher lvls, you'd only get like 10% off their damage.
should you have any questions or unclarities feel free to ask
