Welcome to YT!! Glad to have you here. You have definitely come to the right place to learn about being a great yorkie owner. There is a lot of good information on nutrition here, toys, grooming ect.
I agree on switching your foods - please read some the stickies at the top of the sections. You will also find some good idea for treats - my 2 love Buddy Biscuits from Cloud Star
www.cloudstar.com
As far as the floppy ears, besides shaving, you may need to tape them & keep in mind some yorkies have floppy ears when they are teething.
The pin brush is a great suggestion. I love the Chris Christensen brushes. Also, I recommend a bottle of Buddy Splash from Cloud Star - amazing stuff to get tangles out (they also have great shampoo, conditioner)