Smoke Screen + Lingering Fog
Vault + Acrobatics
Preparation + Backup Plan
Mark for death + Mortal Enemy OR Companion + Bat
Nether Tentacles
Tactical Advantage

Starting, straight vault away from him and mark (if u use this), then spam nether...
Just keep his body a little half in the screen.. Most of his attack wont hit you at that range..
When he scream or raise hand or watever animation, be ready to SS.. After SS, keep the same range I mention above before SS runs out otherwise vault away..
Then repeat till he die..
OR boost ur dps..

Yes. Keep that distance I mention and all of his attack won't hit you unless he charge at you.

His multidirectional orange hook damage wont exceed 30k (for me), so try to buff up your HP to 31k if you really cannot avoid it.

few options:

-yes, run as fast as can.
-tank up yr templar with str, vit and resistant. basically my templar is tougher than me, like i died 4 times, he only died 1 time. 

Dude, templar is damn important la.
It depends on how you gear it. He is actually very easy to gear up since followers get +300% stats from gear. (Grab a lousy blue weapon with high str/vit stats, dps doesnt matter)

Somethings can't be avoided completely like the multidirectional fan hook.
He actually helps to taunt off the boss from you. Giving you time to recover/potion/health pool healing.

My templar is able to survive the entire fight most of the time. (unless he go stand in the fire)

wait till u hear Lyndon rants 24/7