I've had this myself. The night splint shelped a bit, but really drove me properly mad (an my wife) its not easy to sleep with boots on. Had steroid injections which were agony and only lasted a few weeks. Orthotics - no good. Early morning stretches are good, they helped a lot for me.
If I had it now I'd have shockwave therapy. It works great, has good scientific evidence and is even supported by the NHS if you can be lucky enough to find someone to do it. Look at www.sportsorthopaedicspecialist.co.uk. There is some good info there.
Impossible to say, but the smart thing to do is see a sports orthopaedic surgeon who actually knows a bit about running. You prob should have new MRI, but it could all be ITBFS, and nothing to worry about.
An expert would see a stress fracture on X-ray by now, but you need to know what you are looking at. A GP, reading the report may well not get it. MRI is needed only to pick it up in the early stages.
They don't go away if you you don't 1) get relative rest 2) sort out underlying problems. Once healed that should be it, but you can get them again if you don't fix the underlying problem.
There is a machine called Exogen, which is great for healing these things up. Look at www.sportsorthopaedicspecialist.co.uk this guy is a marathon runner / orthopaedic surgeon who had the same problems. Look up exogen on there.
Not sure what is up with your knee but there is a knee specialist who is a sub 3 marathon runner who might be worth a try. Not sure if he is near you. Look at www.sportsorthopaedicspecialist.co.uk ther eis good info on there if nothing else. Good luck