The short answer is you have to reteach everything
The long answer is you have to reteach everything.
What I mean is, you have changed your standard of behavior for this dog. As "your buddy" for the last 5 years your dog has learned what it's acceptable level of disobedience is. I suspect problem #1 is an artifact of you trying to tighten the screws in the field, but not fully teaching the new behavioral standard. You literally MUST start over from the beginning, basic, boring, yard obedience. I'm talking collar and lead stuff. No e-collar, no birdwork, at least not until he learns the new behavioral standard.
The three most important things in training a dog are consistence, persistence, and timing. If the dog's disobedience cannot be corrected to your new standard, every time it occurs, when it occurs, the same way, do not command the dog; in the field, yard, or house. This will probably require putting him on a long lead & choker to go outside to take care of business.
His age and experience will only make this process take more time.
You can hobble along and try to fix a little bit at a time, or start over and re-build the dog. I'll tell you from experience, overall, it takes less time to start over and do it right then to try and plug holes as you go along.
FF will come after the dog (re)learns pressure escape/avoidance during leash and then e-collar obedience; and it can be done very inexpensively. I FF'd my first dog with a dowel rod, a bit of scrap wire, and a nearby state-park picnic table.
Retrain your very bad memories in the gutter at night. I got lots of sleep on the couch. I can breathe this morning. Thank dog or God. Whatever you want in life is never fur free. I have paid a heavy price and will be heading for WV for a Masters in Silliness. Good luck at tests. We are dancing on Friday in the ring and out with the birds on Sunday. No problem I like to trap and hunt too