Actually, I don't see a lot to quibble with in the flatwork photos. You have a good basic design of position, with the exception of your hand and arm. (more about that later.) Still photos don't show looseness terribly well, so I can't really comment on that observation of yours.
The over fences photos are pretty much as you described in your post.
The thing that I noticed the most in the flat photos is that your adorable horse appears relaxed and happy, with his head and neck stretched forward, and he appears to be moving under himself and tracking up. So you can't be doing anything too awful wrong!!!!
Now, for some advice -
1.) Banish the critic from your head and cut yourself a break. You're returning to riding after twelve years, it's not going to come back right away. Enjoy the process of getting back your former skill.
2.) Deal with "looseness" and "all over the place" by - lots of work in two point, stretching down into your heel and wrapping your leg. Avoid the tendency to roll your toe out when putting your leg on. Work without stirrups as much as feasible. 3.)Concetrate on redeveloping your feel. Work at a forward gait on a long or loose rein, try to tell when the inside hind strikes the ground. When you've got it, count one when the inside hind strikes, then the rest of the rhythm "One, two, three, four" - walk "One, two, one, two" - trot "One, two, three, pause, one, two, three" canter. This exercise has the double advantage of silencing all those critical voices in your head. I would avoid sitting the trot or jumping until you feel more secure and more with your horse.
3.) Instead of jumping a single fence, however tiny, which lends itself beautifully to anticipating and jumping ahead, do non-jumping exercises, like trotting over cavaletti, alternating posting and two point, or set canter poles on the ground a set distance of strides apart, canter over them, counting strides and focusing you eye on a spot on the horizon. When you can canter over them calmly with out changing stride and without jumping for the horse, play with adding and leaving out strides.
4.) The one equitation flaw I will point out is your popping elbow. I like that you're riding with a little slack in your rein, apparrently you're having trouble maintaining contact and have decided to loosen the reins. Good choice, and one that will preserve your horse's nice attitude. Work on keeping your elbow close to your body, thumb up, wrist straight and maintaining that straight line from bit to elbow. When you feel your hand and arm following his head and neck again (impossible to do with your elbows out) *then* pick up contact.
Sorry for the novel! Good luck, and post more photos!