My Chaos was quite the handful when she was an adolescent so I feel your pain. And unfortunately there is no other fix, just as other have already said exercise and training. The thing about exercise is that the more they get, the more they need to a certain extent so while it's necessary to keep them sane, it's incredibly important to teach them to sit still sometimes.
One of the things we did with Chaos is we never fed her kibble in her bowl - she got all of it for doing commands or tricks throughout the day, on walks as rewards for paying attention, in treat-dispensing toys, etc. I swear I had kibble crumbs in the pockets of all my jackets and most sweaters.
Of the treat dispensing toys I've found the Kong is great (you said she's not interested but she sounds crazy about food - she will ignore it even with food in it???). We smear PB or low fat cream cheese in it, or put a thick-ish slice of pepperoni (this one is tough to get out), or wedge a cookie that is big enough to not just fall out, but small enough that it won't break into crumbs if she crunches on it. We also used a big round treat ball a lot - basically I'd put 3-4 kibbles into it at a time, and I taught her to bring it to me when it was empty (she could tell by the sound, lol). Putting in too many would just make them fall out fast, defeating the purpose, though that's what I'd start with to get her interested. Even with the toys though you can't just leave her alone until you see how she does with them, otherwise they'll get chewed up as you saw (esp. if empty). We also have several other toys by the Kong company.
We have used other techniques to get Chaos to settle, and I'm sure you'll find some that work for you. One was that I'd sit down with a small bowl of her kibble (kept from a meal as I mentioned before) tell her to lie down and stay, and I would reward her with a kibble periodically. At first it had to be more frequent, but as she learned the routine I was able to space it out more and she would actually fall asleep waiting for the next one. At first she'd jump up when she got the reward but I'd just tell her to lie down again, or you can use a leash at first in case you have a hard time keeping her from running off.
We also do little "jobs" around the house to keep her mind busy. She brings recycling to the kitchen, you could also teach your pup to pick things up that you drop, give her toys a name and ask her to bring you a specific one (we do this with treat dispensing toys and the reward is the treat that I put inside it). The long line is a great idea, I've also made one from climbing rope I got at a hardware store with a clip tied onto it (you'd have to make sure you use a very sturdy knot though!). I then tied knots along the length to make it easier to grab if she makes a dash for it. At first I didn't give her too much room to prevent this though. Personally, I wouldn't trust her offleash, and I wouldn't expect her to stop running away at any point - a leash is a safety device, I'm a big believer in them.