I'm goin' with a dirty camera for the moment for the dust. As suggested, a good cleaning might help, but I would use compressed air or a rubber air blaster (be careful for liquid stuff being expelled). Lens off, mirror up, open the back, where the film is, etc. I do mine occasionally and never have this kind of dust.
It's too hard from your postings to tell about exposure and development - I think you need to print on a normal (grade 2 - 3) paper and go from there. Your negs have to work in your darkroom with your chems, paper, and techniques (and to your taste). If you graze around this forum, you'll find a lot of information, and, as Bethe said, the Ilford site has a lot of "getting started" info.
Also, Ken made good observations about the possible fog. Try another camera to eliminate this, and see if the rebate area is different.
I would also recommend only one film and developer until things start getting predictable.