Bill from PA has a great summary. We (too) usually walk to MGM and EPCOT, and boat back (it often depends on where the boat is in relation to the dock). Bus service is, well, your average bus service, unless you encounter a situation where all of the resorts are piling on one bus, in which case it depends on the order of the stops, and which resort you are at in that que.
Coming back from either AK or MK, grab the first bus for the area, and either hop off and walk, or ride around to the BWV.
Note: DTD bus service before about 6:00 p.m. is very inconsistent, and we have had waits of up to 45 minutes (twice now) from the BWV and BCV, while trying to make somewhat early ADR's. Busses seem to come more frequently the later it gets.