You taunted multiple times before breaking mez simply because taunt is inclined to fail a lot. Taunt either works or doesn't, it doesn't build threat through multiple use.

Says who...

Taunt puts you at the top of the aggro list. If you are already at the top, it does nothing.

I stand corrected, thank you.

some agro tips.

the closer you are to the mob the more agro you can get. So when tanking stand right up on it. Also sitting cause alot of agro, help at low lvls when tuant fails all the time, just use sitting instead. If your grping with an SK and you want to tank, ask them NOT to cast disease cloud and you should be fine. For pally ask them not to cast flash of light. Obsidian shards proc 30DD + AC debuff at lvl 16, try to get two of these.

Distance to mob doesn't matter once inside melee range unless the mob is rooted, then he will prefer his closest target over anyone.

It often didn't seem like snap agro on live because it's only taking the current highest agro number and adding +1 to it. In some cases something else might happen at the same time or a split second afterwards that changed everything.

Example:

Warrior has 1098 agro, enchanter has 1000 agro
Enchanter agro goes up to 1200 from a nuke (made the number up)
Warrior hits TAUNT (which lands) making his agro automatically 1201.

At this point if the warrior kicks, bashes, procs or wahtever, his agro will continue to stay on top.

However, if the warrior doesn't do any additional agro building and the enchanter sits down immediately after the nuke lands then that taunt has just been completely wasted.

Will somebody please clean that enchanter off the walls?

I've noticed that once you hit level 20 and your skills get over 100 points, it starts to work a lot better. It won't be perfect, but Taunt works about 50-75% of the time at that point. But yeah, a SK's disease cloud spell is just insane for agro. If you have an SK in the group, either tell him to lay off that spell, or just let him tank.

Using the same number idea.

If warrior has 1800 agro and next on list has 1000, would a successful taunt bring you to 1801, or 1001? I've heard different stories from different people, some people say if you have top agro, hitting taunt will actually hurt your agro (this is the argument that it will bring you to 1001)

It wouldn't do anything. All it does is place you on the top if it succeeds.