I would just keep Nutrical on hand as long as she is eating good. I've o ly had to use mine twice in a year and a half when I had one sick.
I have heard Eukanoba is not the best food. There is a lot of great ones out there. I have been extremely happy with Natural Balance. It is all life stages and they have small breed with a couple flavors so the pieces are small. My dogs love dried chicken and banana treats...but just give treats in moderation since yorkies are so small. Hopefully someone will answer the rest of your questions.
Oh and the teeth cleaning most recommend once a year. Brush often and maybe wouldn't have to do that much.