First off congrats on your little one and welcome to YT!
You will find out that there are a lot of Yorkies that is picky. It's one of those "breed" things. My little Ahi is still picky and she is about the same age as your baby. I tried many different brands of kibble and canned food. I have to offer her and change her food every few days. Some days she will eat a lot and others not so much. A trainer told me that she will not starve herself and that just keep putting out the same food but I can't do that to my little one.
On the eyes thing (also a breed trait) sometimes some found that using bottle water works better and also changing their diet. Some don't tolerate grain well and it clears up after they eliminate it out of their diet. You can try different things to see what works.
On the chewing yes it may also be a puppy thing but you seem to be doing the correct thing by saying no. Be consistant. Also when he chews on something or someone. Tell him no and replace it with something he can chew on and give praise when he bites on that instead. He will learn quick.
Good luck and if you have anymore questions, everyone here is more than happy to help.
