I'm glad your visit went well and that you got some answers. Behaviorial issues are tough. Ava needs a lot of exercise, too– more than I can give her with walks and playtime. It takes lots of active dogs to tire her out, and she will play nonstop for hours, exhausting them all. We were turned down by several daycares and daycamps before I found one that would take such a high-energy dog. Most have separate play yards for "less social" dogs. So maybe there is a daycare near you that can group Oakley with a prescreened group of dogs that he likes? Or put him in his own run with other dogs in runs on both sides, so he can play and chase with limited contact. You might find that Oakley becomes more at ease once he's used to being around other dogs all the time (with you not there). If you're concerned that the resource guarding could cause problems, ask them not to offer treats or toys or to only make them available in the crate.
A few things that have worked with Ava at home are a flirt pole and a kiddie pool (big successes!) and, occasionally, a frisbee. The treadmill didn't work for us (I was pretty bummed) and neither did those activity balls and IQ cubes. Even if you can't enroll Oakley in agility classes right now, maybe he would enjoy some of the equipment? Can you do private classes or start with a few pieces -- short tunnel, wobble board, stepladder, etc. -- in your living room? That could be a confidence builder for Oakley.
And don't forget to take care of you! Dealing with a challenging dog is very stressful and can affect your health. The stress can really sneak up on you..