I would try my hand at a Reading - Lancaster service. Would probably have some independent utility, and would better leverage the existing Keystone infrastructure (also it makes for easier connections to points west, notably to Pittsburgh). One would be able to catch a bus around lunchtime to make the connection, rather than early in the morning (and vice versa in the afternoon...needless to say, there would have to be at least a midday trip thrown in, and ideally bihourly service or better)
Pottstown to Philadelphia can already be accomplished by taking the #93 bus to Norristown and making your way from there.