Weimer issues

[Mikki]

I'm not a breeder here.

First to ear infection. If you clean out his ears with baby oil and the ear infections are coming back then the dog can have or may has cronic ear infections. He may need a tube in his ear.
Skin licking: It can be everything. I have a Labrador and they are known for their skin problems. (Our Lab is allergic to grass) He is getting Taste of the wild ( fish) and also extra fish oil. On the top of it he is getting Benedryl.
Your dog can have a food allergy. Most dog do react from Corn meal. Dry skin: the skin may need more oil or fat (Lard or olive oil). Fish oil is good and also Flax seed,
Mange: Parent's or grand parents had it, so will have the youngs. It is genetic. Mange can come from mites as well.
Allergy to fleas.

The best is make an allergy test and a deep skin scrape.

I wish you luck

Mikki