I also wear the smallest kids on my back, but only on outings to save me from having to buy a triple strolle; my daughter or one of the other smaller kids goes on my back and the other two little ones sit in the stroller. The only other time I use the carrier is when we are playing outside in winter and I have one who isn't walking yet. I also use it sometimes with my daughter in the house, but not that often now that she is 11 months. It does not hinder being able to care for the others in any way...in fact it helps because then one child is safely out of the way on my back and my arms are free. I never suffer from back problems due to baby wearing.
As for the cloth diapers, I don't rinse in the toilet, but will dump if there is a liner or if it is solid and falls off easily. I lift the seat and plop it right into the water, so it is actually no different than if a child were to poop into the toilet, so I see no health issues there. I always wash my hands after changing diapers anyway, so no difference there either. If there is no liner and it doesn't easily dump, it goes as is into the wet bag. I also love having most of my kids in cloth because I don't have garbage cans full of stinky diapers by the end of the week! Plus, they can play in them at the splash pad without them abosorbing a ton of water and leaking that gel stuff that disposables do (in absence of swim diapers).