You got some very good information here.
The only thing I'm not sure of, though, is about your carry-ons. I know for sure you can check them with Bell Services if your room isn't ready yet. But I question whether they will be automatically delivered to your room along with your DME luggage.
The Bell Services CMs who do the baggage deliveries within the resort are pre-tipped by Disney for the DME luggage (that's why you don't have to be present when your DME luggage arrives). But I'm not sure anyone wants to deliver carry-on luggage to you without the possibility of a tip.
One of the little known but very real perks of DME can help you get into your room earlier. When you check in at the airport's DME Welcome Center, the computer sends a message to your resort that you have checked in and will arrive soon. The resort then looks at your reservation and pre-assigns you a room if one is available that matches your reservation. Even though you're still at the airport, no one else can claim that room -- it's yours if you want it. So if someone arrives at the resort by car 2 minutes later, and they have the same reservation profile as you, AND if yours was the last available room of its type at that time, that person will be told their room isn't ready yet. You arrive by DME bus 45 minutes later and get your room, while that other person might still be waiting for a similar room to become available.
And by the way, you're not TIED to that room. When you check in, if there's something you don't like about it, you're free to ask the CM for a different room, but keep in mind that the "other" room you ask for might not be ready yet.