I think remmie is definitely purebred! He's absolutely adorable!!!
As far as size goes....my newest puppy is 9lbs at 4 months. Yorkies come in all different shapes and sizes and they all have different hair. Remmie may not seem to be the standard Yorkie, but that doesn't mean he's a mix. I have three purebreds and they all look different, feel different, and act different.