You're way ahead of the game since you asked! Don't take this as solid information b/c I'm in the same boat as you in terms of being new. (I've only been in dungeons up to 70, heck I don't even know how to tank swap naturally! I am new. Little leaf on my head, but if I can hold hate so can you!)
So far now that I'm 70 I'm don't have many hate issues. I do happen to miss a mob or two if I don't pull correctly with over power, but I get them back in range and we're good. I noticed I was doing a good amount of over powers but now that I've replaced them with a few steel cyclones I'm good. I then start rotating around my combos as needed, if I feel one is neglected I'll BB him otherwise I keep my dmg boost up and get my 20 beast points. I don't really have many issues not having my gauge filled (I even use the new forbidden Onslaught and Upheaval moves!)
I guess it's easiest to say, start off with Berserk or Unchained if you can, use Infuriate when you can. Overpower and use Steel Cyclone to get a handle on hate, then start with your rotations, once you get the 20% buff either overpower or another steel, then you're free to gather up for next pull or use it for an absorb move.
Adjust this due to how fast things are dying.
Since you can't use Unchained outside of battle I usually use it after my first OP. Weave your cool-downs and switch around between Steel Cyclones (tp free) and Overpowers. Also, now this is just me..not saying this is for anyone else in this world, I ask for TP if needed or sometimes I just get it! This is a co-op game, we're a team, if they can they shouldn't have an issue tossing you a Goad.
Sometimes I start off with throwing an axe, sometimes Onslaught, then take the mobs through and turn them around. So far shoulder rushing them turns them around just fine, some may disagree.
I don't even miss flash. Though maybe a veteran can come in and give you some major details because I'm not that guy.
But so far on my end? Haven't had any real TP issues / Hate issues / Beast Gauge issues, and my healers are still able to burn my eyes with Holy Spam.
And watch out for those healers burst heals, they're wonderful. (Asylum / Excogitation / Earthly Star) less they got to heal me the more they get to blow stuff up every now and then!