Do take a change of clothes etc. in your hand luggage, we "only" had one bag not make the connection to Ouarzazate but I get the impression that, on every flight, they are putting on the bags left from the last flight and, to do that, they have to leave off bags for that flight....
Food was a lot better than I expected, it really helps, however, if you eat either chicken or lamb (or both) as they are on every menu.
The camel trek is not out in the wilderness, use your imagination! Bathrooms aren´t as bad on the trip as I feared but flipflops are good for the gite and desert ones. Hot water was a lottery throughout the trip. Water is about a third of the price outside of the hotels. Take sunscreen, hand sanitiser (anti-camel gel) and a torch. And a cork screw, Moroccan wine is not bad at all, however, in some of the places that you stay you have to buy and bring your own wine, so you need your own tools. Twice you will have to take your overnight things in your backpack but on both occasions our sleeping bags were transported for us, so you don´t need to squeeze them into the backpack as well. Oh, and my top tip, if you are camel trekking at the time of year where everyone is taking sleeping bags, get the camel transporting all the sleeping bags as they make a wonderful cushion....