If you're willing to look outside Montgomery Co., then I'd recommend Media in DelCo and West Chester in ChesCo. Both have very "towny" feels to them and both are county seats. They are pro-pedestrian & have brick-lined streets with plenty to do. I've lived in or very near both & would highly recommend them.

Certainly Glenside , especially Keswick Villiage offers the walkable feel you are looking for ( check out my listing at 59 Chelfield Road in Glenside) , and you are on target with Jenkintown. Without traveling to Doylestown, I would say Chestnut Hill and possibly Flourtown would also be good options to consider.

Conshohocken has all that. In the map link below, you'll find a grocery store at W. Ridge Pike & Butler Pike, restaurants & some shops between 1st and 6th ave on Fayette Street. You can get regional rail at the station at Fayette & Washington St. There are other shops and places to eat scattered around the neighborhood within walking distance. The PA turnpike entrace is about a 2 mile drive. A cab to the airport or center city is probaby about $65.00 so its generally cheaper & easier to take the train.