I second that whole heartedly Jim is ace - he knows dogs, and more importantly he knows people. He helped with a dog I fostered once - it had severe separation anxiety and it barked, constantly, for everything. Jim helped me sort that out, and within 24 hours the barking was under control. He really is excellent.
With regards to the food aggression: I too am not of the mind that taking a food away teaches the dog to respect you. If it feels threatened when you're near it's food it's going to kick off if it thinks you'll take it; that behaviour will just continue to escalate, ie the dog le