Ok, I watched the video, he looks lovely.., I do think that you need to establish a good recall and then just let him be a dog and trot around, have a sniff and explore a bit when he's off leash. at the moment it looks a bit too much like "all work and no play"..as they say...
Both of my dogs are allowed to wander and explore off leash, and when I call, they immediately focus on me and return..the beauty of a good recall.. I never let it go unrecognised when thy come back to me, a "good boy / girl" makes such a difference to them, they love to know that I am pleased with them!
If you are worried about the recall, you could get a longer lead for him to trail.. I always train recall from behind the dog so that the act of turning and coming back is not an alien one. Invariably, when you really need your dog to come back to you, it'll be when he's heading towards something and you're way behind him!
A good stern "no" when he paws or jumps up, and turn away from him, he'll get the message...Save the harsh correction for teaching him that cat is off the menu (if a stern "no" isn't enough)..
He looks lovely..enjoy