I think the tack I'd take for wardens would be as a facillitator to other healers. Like group immunity to knockback, target clears/locks/taunts, to reduction of base heal or crit, stifle/stun/interrupt, and immunity to level decrease. More emergency abilities would kind of go along with their playstyle also - maybe great improvements to their death prevents along with shorter reuses (though there's still the problem with multiple death prevents all using triggers simultaneously, which is a problem with bloodletter with more people using SK tanks now).