Hello, I'm getting so much conflicting information it is hard to know what to do.
We all sympathise there - if you ask 10 different horsepeople's opinions, you'll get 10 conflicting replies!
It just becomes a matter of educating yourself & learning about the pros, cons, effects of different approaches in order to weigh them up.
I bought easycare backcountry trail boots and am waiting for them to come in the mail. But some people are of the opinion that I should shoe him to prevent new bruises and help heal current bruises. Someone said he needs to be up off the sole in order to heal.
Great that you've already ordered boots for him. That should do the trick to provide him with protection for riding. As for shoeing for prevention & healing, shoes do not provide protection to the base of the foot without pads as well, except in that they raise the sole from the ground an extra 8mm or so, which may take it out of harm's way if on flat surfaces. Shoes also put constant pressure on the walls, laminae and often the edges of the sole. If the sole is thin, this constant pressure can cause bruising/abscesses of itself.
Shoes, or boots for that matter, don't do anything to aid healing. That will just take time. I don't believe jacking them up from their soles - peripherally loading walls - is helpful, as it just transfers the areas of strain & damage, and taking the sole out of use & peripherally loading causes it to become weaker & thinner IME. But of course, thin/flat soles do need protection & support, as the 'armour plating' isn't thick enough to protect the internal foot.
I don't know what to do because last night he was almost imobile.
Sounds like it may have become an abscess if he's that sore. Soaking in epsom salts or such can allow horn to soften for the infection to erupt & clear. I would not generally advise getting a vet/farrier to 'dig for it'.
Everyone says Appaloosas have notoriously bad feet he needs shoes and then they say if I put shoes on him they will never toughen up.
Hmm, down to that 'if you asked 10 horsepeople' again, as far as breed traits, to a big degree IME & I'd have to say that most appys I've met, inc. a few I've owned(hence my username here) have had great, strong feet. While genetics do play a part, I believe that generally speaking, 'good' hooves are made, not born/bred. It's predominently 'nurture' over 'nature'.
I think hooves need to be/become healthy before they can begin to 'toughen up', and IME shoes are contraindicated for building/regaining health generally. As for toughening up, you can think of this similarly to toughening your own feet. If you were to walk barefoot daily, as much as you could over whatever surface, but being careful not to do damage by doing too much/too hard, you would develop thick, calloused skin on your soles that would allow you to do gradually more & more. If however, you avoided using your soles, the skin would become/remain thin & soft. If you don't use it, you lose it.