Millvale is the key to the route. Coming from the hospitals, take:
Bayard->Devonshire->Millvale (via the parking lot there or a hop along Centre)->Friendship or Liberty and Main
To go to Squill, I'd reverse up to Devonshire, then hop over to Morewood at some point, go through CMU to Frew or Tech Street then climb along Schenley Dr.