I have a 4 ft chain-link fence all around my back yard. I fostered over 40 dogs in the last 3 years and only one went over it, a young boxer mix. None of my pyrs have ever gone over it. I don't know what I'm doing right. For the boxer, I ended up using a wire run between the house and a tree.
Chewing has been the hardest part for me as a dogowner. My pyrs and fosters have chewed 2 couches, pillows, tools, solar walk lights, doors, walls, my irrigation system and of course shoes. Xena, my current chewer didn't stop her chewing until she was almost 2 years, though she slowed down by 1 1/2. Even now, at over 3 years, she gets an urge for the plastic planters by the greenhouse.
They do grow out of it. Just pack away anything that it would hurt to lose.