No worries at all!
I wouldn't say it required constant paddling, but i think due to my weight it certainly bogs down a little more than it will do for you. I certainly don't race with it and just tend to leisurely cruise along. You will notice a big improvement in the move up to 14' more than anything, especially it's ability to go straight. One of the hardest parts is turning round on a canal as they can be narrow at times!
You seem quite fixed on rear bungees, what do you tend to carry? Are you planning on some longer trips where you'll have camping equipment etc? I find i don't really use the rear bungees, but then at the same time i very rarely carry stuff on my board. I might have some flip flips and a bottle for drinking, but that's around it. My car keys i try and palm off on my mate who takes a proper dry bag, otherwise i just stick them in a pocket as i'm unlikely to fall in.
I recall when i bought mine they were willing to let me try the 27" version and then swap for the 30" if i decided it was too unstable. Could always maybe ask if they'd be willing to try that? It was back when Gary at Sup Inflatables wanted a 27" demo board though so it might not be an option for them anymore.