We’ve stayed at YC once (will be there next year), and found either to work. As others said, definitely walk to Epcot. Maybe if the boat is there and loading I’d ride it, but it’s honestly just easier to walk.
HS is a toss up. I’d say boat unless you just miss it. Here’s our experience though. Our first morning we just missed the boat loading at YC so we walked. We beat the boat to HS. The next morning the boat was at boardwalk and heading to YC. We decided to walk again since it was quicker. Well the boat beat us that day. So not sure if something held it up the first day or if the second maybe it was full or something and didn’t go to swan/dolphin. The third morning we went to HS we just waited for the boat.
It’s a nice easy walk, but with so much walking already I vote for saving the mile on your feet. Like I said, I would maybe walk if we just missed it though because I’m not sure how quickly another would come.