Can you just walk around the marina and look at the boats/water/etc? We just want to take it all in, is that possible?

Yes. And you are able to ride the boats, monorails and buses sound Want Disney World at no charge

The whole place is amazing to wander around. I did read that they are not allowing any one to just park and come in right now unless you have dinner reservations. But you can come over via bus, boat or maby a minnie van.