With ears itching it could be ear mites, an infection or possibly both, only a vet can tell you. Either one can be treated easily and not too expensively.
The teeth are retained puppy teeth and are best removed when he is neutered. At his age, most that would fall out on their own have done so already. The cost will vary depending upon where you live. In our area (less expensive than most) a spay, pre-op blood work and having 10 puppy teeth removed cost me close to $300.
Any yorkie with longer hair will tangle and mat, some more than others depending on coat type. With grooming daily you can keep the tangling and mats to a minimum....or you can choose to keep him cut down and almost completely eliminate the tangling altogether.
Good luck and let us know how it goes with is trial visit.
