Push mechanics, head toward your respective sideline and clean up
For the F, yes. In the OP the ball is snapped from the B-30 and B has a "clear path", so you're probably not going to get to the sideline in time do anything beside pick up a cheap shot behind the play, but you never know what's going to happen. The B should be doing the same thing toward the other side similar to a fake kick.
For the S, stay inside and clean up with the U. Stay with the pile of linemen until everybody is up and untangled. Once the interior is separated and the return starts, split the field working inside out while H/B and L/F work outside in.
