I'm not sure if it would benefit from willpower, what I do know is that it procs off the dark charge and force lightning heals.
Well Willpower boosts our total 'bonus healing' - only our self-heals don't benefit from this as they are percentage based. As this is a set amount I assume it will benefit from the bonus healing we receive from Willpower and Power.
I'd say the absorb relic is a given and I prefer the PVP +defense relic for the 2nd slot. More total mitigation points.
I know the War Hero relic is currently BiS but don't you think the stats provided by the Dread Guard relics surpasses the WH one? At least until the Elite WH Imperilling Serenity relic comes out. BioWare said after 1.3 they would never make PvP gear viable for end-game PvE and vice-versa