Trhill of the Hunt seems overrated to me, in yolo you simply have to get +30% dr while stunned, since pretty much everyone stuns you the second you get jumped.
Also I think Energy Rebounder is a very good 2nd t3 utility, since if you are not too cheap with your shield (this is not 2.10 anymore ) you can get the shield back when it matters, although this probably means 2 shields in a game, but i personally love the breathing room it gives.
I do not agree that mercs are lagging behind anything atm. We depend on how good our dps is, ofc, because we can only survive for so long but then again that's the same thing for all healers. You have to pretty much do what Exi said, kite smartly, kb, cc, do whatever you can to buy yourself time. Always look where the ranged dpsers are so you can LoS them and always kb the melees in annoying spots (**** it, even net + kb to take a dps out of a fight as a sort of soft cc. this is a desperate move, ofc, since net is love & life and gets you a kill before they kill you, sometimes). I'd also suggest to drop interrupt immunity in shield (the herresy ) for +4s in HtL. Kite kite kite. And clench your butt when you can't kite and praise jesus for +30% dr while stunned.
If it so happens that you are not getting tunneled by 3 dpsers, you should not move so much, you should plant your feet in the ground and cast. We can dish out insane healing and burst healing (srsly, healing scan, supercharge, emergency scan, healing scan is so good) and we really need supercharge for heat management so stop and cast when the situation allows it.
Oh and zoom out the camera, so you can see the ranged bastards that are pummeling your health.
Really loved the clip and the song, nice deviation from your ordinary pvp clip