Yes. Simply enter your confirmation number in MDE, like you would any other Disney reservation. Your reservation details will then be stored, and you will be able to customize MagicBands, make dining reservations (beginning 180 days from arrival, for your entire stay up to 10 days), etc. Your MagicBands and luggage tags will be mailed to you about a month before you travel.
If you want the DDP, you'll need to go through David's (giving them a CC# to pass on to the Member from whom you're renting, as they are the ones that have to set it up for you.) The dining plan is the only part of the reservation where you need the member's assistance. Everything else you will manage yourself through MDE.
At some point before your FP+ window opens (60 days from arrival), you'll need to buy Disney tickets (unless you already have annual passes, or have already linked valid tickets to your account) and link them to MDE, as well. You can buy them online directly from Disney, or from a reputable authorized reseller like Undercover Tourist. If you want MemoryMaker, etc., you can set that up through your MDE account as usual, too.
If you are flying in, once you have your plans in place, you can use this link to set up your Disney's Magical Express transportation:
https://disneyworld.disney.go.com/airport-transportation-reservation/
Also, as you mentioned, travel insurance is always a good idea when somebody has a medical issue, and you'll want to purchase it within a few days of your rental deposit if you want to be eligible for "cancel for any reason" coverage.
While you're making plans and formulating your packing list over the next month, I also recommend checking out the detailed room tours and amenities lists for your particular villa. The "your first visit" website has some great information for each villa/size category- so does
http://allears.net/acc/dvc12bvamenities.htm. Each resort sets up its villas a little differently, and browsing photos and floor plans ahead of time will help you visualize the storage space (in a 2-bedroom villa, you will have TONS of room, not to mention all the comforts of a full kitchen and washer/dryer!!!), and will prevent you from inadvertently packing things that are already being provided for you (e.g., dish detergent and sponge, can opener, dishes and paper towels, etc.), or from forgetting to pack things that aren't (e.g., you'll get a coffee filter pack or two for your coffeemaker -- but that's it, so you'll need to bring your own for subsequent days!).
Also, just a reminder: with a DVC rental, you won't get daily housekeeping services - just "trash and towel" service on day 4 of your stay. When my family stayed in a 2-BR villa at Wilderness Lodge, we found that the lack of daily housekeeping made no difference whatsoever. We had a broom, vacuum, etc. in the villa that we could use to clean up after ourselves here and there, and we don't mind re-using towels or making our own beds [poorly]. If you decide that you want to pay for more frequent housekeeping, that's something you can set up at the front desk when you arrive.