I didn't propose at DC, but I did have the Elite Package to celebrate our VR at Disney. To keep my answer short - DC is AMAZING and the perfect place to propose. With the Elite Package you can make it AWESOME!
The dolphin buoy thing worked like this for me...
You tell the what you want the buoy to say ahead of time. While you're having your dolphin swim, the host you're assigned is in your private cabana putting a dozen roses, champagne and flutes, truffle chocolates and your photo in the wooden frame in your cabana so when you get back it's all laid out and looks beautiful!
During the swim our trainer asked for volunteers to help her with a trick with the dolphin, my wife volunteered along with several other people but it was all set up!! My wife was picked and she was told to make a particular action and the dolphin came to her with buoy in it's mouth with the message on it.
Honestly, if I were proposing again, I'd defintely do it at DC with the Elite Package because, not only do you get the dolphin, when you get back to the cabana it will look beautiful and romantic. The private cabana is a nice place too to celebrate together and enjoy the small animal meet and greet.
Our host was Kaitlynn and she was fantastic! She will do whatever she can to help you so I would recommend that you ask for her ahead of time if you can. She is very discrete but will do anything to make your day special.
