hi and welcome
i'm not an expert with yorkies because mine is only 6 monthes old, but i've read alot on here and learned from others.
The barking maybe just because he's excited and in a new place. he's probably trying to adjust to his surroundings. which Tyke barks when someone drives up or he hears a noise outside.
the food issue- you may have to ask what kind of dry food they were feeding him. when i brought Tyke home he wouldn't eat anything and I called the breeder and found out what kind he was fed and when i bought it he started eating it.
being alone- i know that alot of people on here work and they have to leave their dogs, but your schedule sounds alot like mine. I go to work at 9 and put Tyke in the bedroom with his bed, toys, food, & water, and his pee pad. then i come home at lunch usually 12-1. that's when i feed him his soft food.
and take him out. then i come home at 5. he does ok being left alone. he's just really glad to see us when we come home. i also tell him i'll be back in a little bit and i give him treats when i leave. hope this helps some
