here's two low hill routes from wilkinsburg to downtown that avoids going over squirell hill.
this one you could take the jail trail to town instead of fifth.
7.7 miles: http://www.bikely.com/maps/bike-path/Wilkinsburg-to-Downtown-Avoiding-Big-Bad-Fifth-mostly-and-Penn
This one goes through homewood, east lib, bloomfield, lawrenceville and also avoids penn and fifth
your route will depend on if you want to avoid going over squirell hill or going around it. i recommend staying off of penn ave through
check out bikely.com there are a bunch of routes on there for swissvale.