I will say, as a Glad, when tanking, I use abilities from EVERY SINGLE CLASS....
at least one 30+ (And in most cases 40+) ability from each of them....
Glad is very very involved...
To be a good damage dealer you can get by with just your class abilities... I wouldn't even use attack buffs on the ogre or Batraal...
To be the best healer you need Conj to 50, thaum to 48, and Out of sight from Archer....

But to be the best tank....
Glad 50, shield 50, obviously.... (Shield is given to you now, but when I came up, shield ranks were hard earned)
I'm not gonna list Glad and Shield abilities... Just know that Ambidexterity is now awesome
Mrd - Defender II, possibly bloodbath II, Foresight II, Disorient II, barbaric Yawp
Pug - Second Wind II, featherfoot II, accomplice
Lancer - Diversion, Invigorate II + twisting Vice used to be a monster combo for a tank until they nerfed twisting vice....
Archer - Decoy, barrage (its a weaponskill that increases enmity)
Conj and Thaum heals....