Thinking of starting tanking, need advice.

[Mikazuki_Aura]

I don't have any issues with Steel Cyclone usage. The very first pack eats the initial SC from Infuriate, then after that I generally generate enough of it. Storm's Path generates this more quickly than the other 3rd combo skills do, and its selfheal helps a bit with keeping me up while taking several mobs, before switching to the Butcher's Block rotation after most of the mobs have eaten one Maim debuff each.

The loss of potency from not using BB is generally compensated by the increased damage the slasher-type DPS classes get out of AoEing SP'd mobs, and this gives more SCs to use for both the AoE emnity as well as damage (since the mobs the later ones hit are Maimed). In general I enter most fights with nearly 100 BG, then SC as necessary to avoid going over 100 or losing threat. If running out of SCs you're probably BBing a bit too much and SPing too rarely.

Overpower spamming is an emergency technique really. If the SC rotation is working normally it should be impossible for DPS to pull aggro off you. It's easier to pull aggro off a PLD since they don't normally use Flash that often being a zero damage skill, while SC is an integral part of the normal attacks. And using overpower drains TP, which limits how soon you can engage the next mob set without relying on either Goad or risking running out of TP (and having aggro cascade over your party).

WAR has more self-sustain, which can be good for running roulettes since you can keep yourself alive to finish off a boss even if everyone else dies. PLD on the other hand is more optimal nowadays if you're running with people you can trust to do their jobs properly.