At Epcot, it's very close to the front, and it was close to the front at MK but that has been worked on recently so I'm not sure where it is now.
There is rhyme or reason to which resorts are where in the bus line up at the parks. You may be very close to a park entrance at one park but the furthest away at another. And being in a deluxe vs value resort doesn't much matter.
While they can change the stops for each resort, it really doesn't happen all that often. I know that we have always gone to the same numbered stop for BW each time..and that is over the past 8 years or so. Same with POR and Pop. THey just haven't changed.