This will be a long post but I have a lot to say.
First, the most obvious - ban AGM. This SHOULD stay here as is. There's a reason Earl and a lot of other Alliance have AGM's. It's because (NOT BECAUSE YOU WORKED HARD) they are Alliance. Back in the day AP was a huge, and still is, Alliance server. Nearly every Alliance twink that tried for AGM has one. Nearly every Horde one does not. You want to talk about effort? Horde characters take a hell of a lot more effort in most cases. You have to get a fishing hat. You have to get AGM against 85s that were mostly Alliance. CRZ changed some of that in that there are now more 90s, but all that changed is now no one gets an AGM. There's a reason some of the most dedicated twinkers in the game don't have AGM Horde side. We're talking about people who farmed 3/3 bracers dedicated. I'm not expecting that to full convince you, so lets talk about why AGM is going to be huge for actual gameplay. AGM is groundbreaking. It means that you get a bubble UNLESS the other team has a shaman. That's essentially going to force every team that doesn't have an AGM to go w/ a shaman to counter that. That's terrible for gameplay because most teams are going to become Prot/Hunter/RSham instead of just Prot/Hunter/X.
Let's move on to banning certain comps. We have to ban resto druids and protection paladins. These two classes are lumped together because they are too overpowered. Resto Druids that are good will not die. I can all but guarantee that the resto druid I play will not die. I will have 2200 health, maybe 2300 with a warlock. That makes me essentially unstoppable. If you play this bracket you understand how strong resto druids heals are. They tick for over 250 PER TICK. That's insane. You can't outdamage that even with a purge happy shaman. People always assume that shamans can just purge 24/7 but you have to understand that a team that puts out pressure is going to make it very hard for a shaman to have globals to purge. Prot Paladins are OP on the other end of the spectrum. A 600-700 crit which happens regularly for Stephen is ridiculous enough as is. It's even more OP when you consider the silence that goes with it. Prot/Hunter is not OP, Prot/X is. The only reason Prot/Hunter is the favored comp has nothing to do with how strong hunter is, but rather the CC available to it. Hunters have so much CC that Prot paladins can just OP themselves to victory. Moreover, prot paladin has THE LOWEST skill cap in this bracket. Look at Swagcleavic's vids. His UI should tell you all you need to do to be an amazing prot paladin.
If you ban these two classes you get rid of most of the complaints in the game. You banned prot paladin so there goes the prot paladin/rogue rule. The only other rule that you would then have to implement is the feral/rogue ban. Feral /Rogue should not be a viable comp. They both can global players (literally) by a 5 point FB or Eviscerate + a melee swing). Putting the two together just means: Train person X until one of us one shots him. We've seen this happen time and time again w/ that comp. Hell the favored team by most people lost to an average team simply because the rogue one shot the healer every once in a while.
I think all offhealing should be fine minus spriests. Without prot paladins you would have, ret paladins, shadow priests, enh and ele shamans and feral druids. Ferals heals are purgeable, and also are not spammable. Moreover you can kill through a feral rejuv. Ret paladins are not that strong and don't have an OP blanket silence so they are a) probably not going to be played and b) are fine offhealing. Shadow Priests have very strong offheals but also very little pressure compared to the other DPS. Ele and Enh bring not a lot to the table and their heals will run them OOM (or at the cost of any pressure at all). Spriests are basically disc priests with mind blast instead of penance so they are just double healers basically which is dumb w/ classes like rogues and ferals able to one shot. Fuck that shit.
So basically my rules would be
1) No AGM (speaking of which - please don't take the opinions of people who are not actually in the tournament. Most of the players playing don't even have AGMs)
2) No Prot Paladin
3) Offhealing fine minus Spriest. If you really wanted to, just allow all of these classes and say they can't heal or they forfeit. I'd be fine w/ the latter rule and it would be pretty simple.
I can't stress this enough. If you want a legit good tournament to watch that gets your tourney, guild and you attention ban prot paladins. Otherwise these games are going to suck (and this is coming from one of the few arena players that plays constantly).