Exploiting is only against the rules if you're exploiting certain things. You can exploit class imbalances to win in arenas, for example. Suvega's definition is pretty accurate.

Unless you adversely effect the economy or bother other players I doubt you'll get banned. Worst case you get rolled back, and even then I doubt they would unless you find a way to get to 70 in under 24h unrested.

In 2.0 macros pretty much went from 150k xp/hour usefulness to 5k xp/hour usefulness. You could pretty much have had an entire raid macroed to one button back then and would only need to worry about movement. Heals that always target the lowest raid member? Easy, even down ranks for you. Programmed dps cycle that checks for buffs and debuffs that proc and uses cooldowns? You got it. Stop casting if your threat is too high? I think we had this. Someone even had a healer that afk-healed AV by using autofollow for movement and just mashed one button while watching tv or something. So does that mean we shouldn't be discussing macros that work now since blizzard removed them? The only difference here is that one was public.