Thanks for posting this, Bigfish. Since I'm using a mixed group, this should make for some interesting challenges. But being able to run the group through a standard tank/spank sequence with only one or two buttons seems pretty amazing. You can even queue up heals, if I understand this correctly.

Just a thought here, you are going through an aweful lot of work in the making of macro's to get around a limitation they specifically put into macro's... I would personally consider this to fall into the very dark gray area right next to exploiting.
I think that aside from the fact that it can be done via the basic macro UI (in which case it wouldn't be an exploit, though Blizzard could change or remove the functionality if they felt it was better than they intended it to be), we need to take into account that this works well when you're facing a standard fight without too many different phases or factors to consider. If things break down or you need to address a sudden change in the fight (something as simple as an aggro switch, even) I think it's likely that your efficiency would dip severely. If you could one-button spam your way through instances without a hitch, I could see the problem. But there aren't that many straight-up tank/spank fights in instances anymore.