It wasn't his place, but to a certain extent, he wasn't really wrong in either situation. That isn't really how you should talk to your suppliers. However, scolding Lorelai over it, and especially in front of one of her employees was really not cool. Maybe say something quietly to her after work.
And, I don't think I would let my daughter drive a homemade car until I knew it had been checked out by a mechanic, but as soon as he started making Gypsy do it over and over, that was where he got on my nerves. He was even right on the Chinese food thing. We've seen scenes of the girls going through the fridge and throwing out leftover pizzas and Chinese food. They are completely wasteful. They even had multiple pizza boxes in the fried not knowing which was from which day. Really? Why would you order more pizza when you already had some and how many times do you eat pizza in a two week period anyway?