The only thing I can think the fur dirt might be flea poop. Take the dirt, put it on a white paper towel, and dampen a little. If it turns red, it is flea poop...if not I have no idea what.

As for the ears, my cats had a bout of bacterial overgrowth in their ears a few months back not associated with ear mites or anything. The vet could never figure out what caused it; but I had noticed Whispy had icky ears so I cleaned them. I guess I didn't clean the tip of the ear cleaner well enough because I gave it to Callie and Shadow. Callie's ears were so bad that she had to be anesthetized and have them cleaned out by the vet. Poor girl's ears hurt so bad. I'm such a horrible Meowmie. Eventually their ears cleared up with medicine.