Nope, i'm playing both accounts at the same time, and neither do anything without my say so.
Blizzard have said, on numerous occasions, that multiboxing is fine, as long as there is no automation... nothing of mine is. They've also said they have people inside blizzard 5boxing

My Shamans healing macros use my Hunters target, assist him and heal the targets target. So however i'm targetting, whoever that person is targetting gets healed. Needs some tweaking for group healing.
Keyclone is a software KVM, and Blizzard have stated its ok to use it as it is not modifying anything in game.
I actually accidentally looted something on my Hunter i meant to loot for my Shaman, i put the request on my Shaman and he said 'oh, the Hunter must put the request in'. I said, 'i'm dualboxing!

'. Popped the request in got it all sorted and his final message was 'Have a good evening, and i hope you aren't mistaken for a bot!'. GM didn't care

It's basically i'm doing twice as much work and it does have some disadvantages like movement is pretty much anchored to follow my Hunter)... and its nothing that couldn't be emulated by another person grouping up.
£16 a month is not a large amount of money ;P