Wow, that really is terrible looking damage.
I don't know exactly what you've got there, but its possible the tree might need to be cut in the future to allow a shorter stump to put out new shoots. I would leave doing this until you're sure the upper part is dying off.
In the meantime, the main exposed area really needs to be protected. I wouldn't advise using tar paint. Instead, wrap the exposed area with clingfilm to minimize further peeling. Wrap the film around and around the trunk so it doesn't shift then bind with some poly string or hemp. Keep a close eye all season on it in case there are fungal problems at work; if so, unwrap the plastic and let it air dry. You'll find later in the season that the clingfilm will have to be removed as the trunk expands, then rewrapped and tied. You never want to have binding marks on the trunk.
Another method is to find pieces of bark from another apple tree, perhaps one on its last legs, and use that bark to shield the exposed area. Cover as much area as possible, tie on with string. And watch closely for eventual binding as the trunk expands.
For your winters, I'd advise wrapping the whole affected area with poly to avoid drying out by the winds. And staking the tree to the windward side is a must. Trees shouldn't be allowed to flop about like you describe. There should be only gentle swaying or there's trouble.
The splitting bark on branches almost looks like sudden excessive water intake caught out by rapid frost or heat. You see this a lot with toms that weren't watered regular, then had a sudden glut of water, and the skin bursts. Not much you can do about tree branches, but the clingfilm trick might work so the bark can catch up by keeping moisture levels more steady.