Since all BCV rooms start from the connection to the main hotel and stretch toward the parking lot, you would request "close to lobby" to shorten your walk to anywhere except the bus stop, which is about the same walk no matter where you are in BCV.
We got stuck at the far end and we found it was a long walk to the food, Stormalong Bay, dock, anywhere except the quiet pool and bus stop.
When walking to EPCOT, you can follow a path along the woods line past the first floor patios around to a little gate.
We found the walk to EPCOT was 10-15 minutes (with 6 year old). We did not walk to MGM with our 6 year old but we have from Boardwalk, where it is 15-20 minutes so I would have said a little longer from BCV, as much as 30 minutes. I could do it in 20 but only if I power walk.