You want a simple, viable solution, enable a dps/threat meter that is optional and only usable in ops, and does not work unless enabled before a fight. Now heres the catch and the simplest answer to all your problems. DO NOT ALLOW A COPY/PASTE FUNCTION. The biggest issues in my experience from WoW would be raid/party leader, hey you suck, post meters and everyone votes to kick the "noob". Its one thing for someone to say you suck and heres why, spam the meters in general because you can. Its entirely another for someone to say you suck and have nothing to back up their words other then my dmg meter says this... does it, prove it?...
Another option would, make it a guild perk only usable when an op/fp consists of 75% guild members.
I personally would love a dmg meter, not to flame other people but to simply better myself. I dont even think it needs to be specific in terms of abilities, I would just like to know that if I do 1000 dps on boss x on date y, I want to know what I do next time to make sure I am constantly improving and if Im not it forces me to figure out why, make adjustments and try it agian.