"Waffles"'s page

What a hoot.

It's not really clear. I allow Rake-Release-Full Attack because that's [how I interpret] what's written.

FTFY

No, because maintaining the grapple is a standard action.

Most creatures have a limited selection of choices when choosing to maintain (damage, move or pin).

Rake is simply an additional option. Others exist as well, such as the Crocodile's Death Roll.

If you want the Lion to utilize its claw/claw/bite again, then you'd have to drop the grapple as a free action at the start of its turn, rather than spending a standard action to maintain.

The Owlbear doesn't have the anatomy to wield weapons anyways, even if it learned proficiency. Its body type is quadruped (since it's just a reskinned Bear), not biped.