Hi,
I walked back from Fantasia mini-golf (I think that's the one) when we stayed at the BCV in June. It wasn't bad at all, maybe 10-15min. In fact it would have been bordering on enjoyable, but I was carrying a very hot and tired three year old at the time.
As far as the boats, I'm not sure how often they run, but I think they are running the route from the the Boardwalk area resorts to MGM so I'm guessing twice an hour?