Thoughts:
Who is the primary target for DS? Resort guests arriving by Magical Motorcoach, or locals/outside the bubble guests arriving by car?
If it is outside guests, then having the 'dead center' of the park by a parking garage makes sense. If it is Resort Guests, not so much.
On the surface it would 'seem' that having the Bus depot 'left of center' is better then putting it at the other side. IIRC, before expansion the Marketplace got the huge part of the business. But now, with the bus landing being a 'mini spoke' of 3 sections, and the Marketplace being the far off 4th, it means the Marketplace needs to make up for it's lack of convenience by delivering content that guests arriving via the Magical Motorcoach are willing to walk over to. With the AK now having a 'Emporium' like store, there is even less reason to go to the Disney Store for general Disney plush - every park has a big place where you can get it. You need something GREAT at the other end by the Rainforest Cafe. Guests who work sedentary jobs and live sedentary lives are already doing far, far, more walking then they normally do in a month by touring the swamps. They don't want to do more, especially if it is for stuff that they can get in the parks...
Not having a boat dock near the bus hub reminds me of a ski mountain that doesn't have a lift all the way to the top - the gondola only get's you 3 quarters of the way up, then you have to ski a few hundred yards to get to a chairlift that get's you the rest of the way to the top.
If guests never chose walking over waiting to save time, the Friendship boats would not exist.
Guests not having bags - is it Resort Guests, or Outside Guests? Resort Guests can have their purchases sent back to their hotel (I assume that this is true at non Disney run stores as well).
For non Disney businesses there, it just isn't about sales - it's about Brand Awareness. But Brand Awareness only goes so far if guests aren't buying your product.
So, when some of these businesses eventually fail, who takes their place? Or since they have empty places in the parks, they'll extend that to empty places in DS as well...