Resilience is what you need, once you got 600+ resi, i highly recommand to find yourself a dedicated healer to join you in BG. That makes you atleast double as effective, since you don't have to waste time healing yourself up -> you kill the oposing faction faster -> faster node/flag cap.

I like eots and AV best, hate AB and sota most.

Problem with low resi is that you're dead before you can even try to heal yourself up. If there's a healer with you, who's out of range of the AoE stun/fear/silence he should have time to keep you alive untill you can cast a round robin lesser healing wave on yourself. Or chain heal if you're pretty sure you'll finish the cast(no priest/lock or BE running towards you)..

SP is not really the problem, i run with 3k SP and i'm actually considering to lower it and get stam trink from frost emblems and Warr Wrathfull shield, just for lolz in BG.