Is a hold short expected when given taxi directions to a runway?
Yes.  A taxi clearance enables you to taxi an aircraft through a controlled movement area within the terms of the clearance given by ground control.  Entering an active runway requires an explicit and separate clearance from the tower to do so.  

In addition, crossing any runway which intersects your taxi path requires an explicit clearance from ground control to do so.  This clearance can be included in the original taxi clearance or a separate clearance wile your aircraft is currently taxiing.  If you reach the hold lines of an intersecting runway, you must hold short unti you are cleared to cross by ground control.