So, being serious here... as a WHM main who is deeply enjoying SGE, and who has been talking to some friends who've struggled with the new job, there's something I know they stumbled with that I feel like it's worth noting. I don't know whether it's where you're having issues, Sturm, but it might be more generally useful to other folks even if not.
Nearly all of sage's AoE mitigation/buff options are entirely viable for single-target scenarios, such as dealing with the tank's damage during a big pull.
Already used Haima, so it's on cooldown? Panhaima makes a great backup! Yeah, Panhaima's only 6 stacks of 200 potency mitigation (the initial shield, plus the five 'backup' charges it puts on as a stacked buff to reapply the shield when it's depleted) instead of 300 potency, but that's still 1200 potency of mitigation on the tank for up to 15s, which honestly is a respectable single-target shield.
(As a bonus, it's also mitigation on all the DPS, in case they stand in the bad.)
Kerachole's just flat out 15s of 10% damage mitigation -- it's the same mitigation as Taurochole, as an AoE. (Minus Taurochole's up-front healing, replaced with a regen.)
Physis II is 650 potency of AoE regen healing over 15 seconds, but it also gives a 10s buff that increases all incoming healing by 10%; tossing that down for a little extra 'oomph' when a tank's seeming a bit squishy can really help buff your other healing.
Holos is only 300 potency of AoE heal, which seems pretty tiny... but it's also 20 seconds of 10% damage mitigation, which isn't nothing during a trash pull. You can throw that one down even if only the tank will benefit from the mitigation.
The fact that I have this veritable buffet of mitigation options -- even if some are AoEs rather than single target -- makes me feel like I have more than enough kit on sage to deal with basically anything. Possibly beyond what's reasonable.