Peder, the donors and carers were the same people. They were carers first until they were called to be donors. Kathy, for example, was a carer for a long time (IIRC, 12 years) whereas Tommy, for example, was only a carer for a short time, as was Ruth.
I can't remember ever reading of those who were in charge, though I agree there must have been someone(s) in charge of the whole operation... but towards the end, Tommy and Kathy go off to find out if they can prolong their lives together, and they don't know who they're to go to, but assume it's Madame. It turns out not to be her afterall, so we're left wondering again.
The donors/carers were cloned from people who they referred to as a "likely", I think, although from the sounds of it, these models weren't aware of their clones? Maybe, maybe not, we'll never know.
But as to who is responsible for the whole charade, the Hailsham students did wonder, did try to find out, but with little success. Aside from that, they were the ones that acted passively.
I think it's a little far-fetched to aliken the donors/carers with "couch potatoes" too, but took it to mean that people don't dare to break the mold, and they maybe should?