We've done this trip many times at different times of day. The quickest route is to take bus from AKL to DHS and walk down path to Boardwalk. The second quickest route is to take bus to AK and then take the Swan Dolphin Bus get off at the first stop and walk to the Boardwalk. The first is quicker but a much longer walk. The second is a much shorter walk but you will probably wait longer for the Swan/Dolphin Bus at AK
When we go to any of the EPCOT resorts we take bus to DHS and then boat to resort. We've always had at least one kid with us and thought the walk was too long for them.
I can't remember where I found this link, but I keep it bookmarked. It's a transportation wizard for Disney. You might find it helpful too =-) It gives you all the transportation possibilities from place to place, and lists their appx. times.
http://www.ourlaughingplace.com/asp/twiz.aspx
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