I think there is unbalance gameplay where dmg taken from burn effect per turn in battle are too big since fire recistant like not help much it realy pissed. And about tank cover skil i think its rather useless cause boss still hit dps much is luck count on that? Like tank should hv low luck to be more likely get hit?.
The "Badly Burning" debuff does 30% MaxHp damage, regardless of your defense or resistance values. The fire resistance only helps against fire element attacks/spells, not against debuffs.
The targeting of the enemies is randomized. You increase the chance for them to attack your tank by using his abilities, but it's never a 100% chance for them to attack him.
Luck affects only the chance of getting affected by negative status effects. It doesn't change your aggro chance, drops, or evasion/crit chance.