http://www.shippd.org/pa%20titles/PAbikelaws.pdf

Section 3505.b allows you to use the shoulder so if there is nobody in front of you in the shoulder how can going to the front be illegal?

I can't pass on the right if it means leaving the roadway AND "roadway" means pavement excluding sidewalk, shoulder/berm THEREFORE operating bicycle on shoulder = no passing on right

That's how my brain interprets it. If I were riding in a city, I'd probably filter up the right past stopped traffic, but out on the country roads in my area, there's really no reason to. It only invites motorist frustration and possible right hooks.