No, you don't have a world where gays can marry and weed is legalized, but you can't buy a cheeseburger at McDonalds. If we're gonna go on full force with allowing "freedom of choice", you have to allow people to have the freedom to go to McDonalds, or the freedom to not go. It's up to them.
What about the freedom of animals to choose to not be killed for food?
They are animals. They are food. End of story.
So, if I decided to eat one of my parents pet cats tomorrow, wouldn't that cat, as a house pet, valued member of the family, and sentient being have the right not to be eaten?
Not at all. Your parents, rather, have a right to not have their cat stolen and murdered. More to the point, you stain yourself by doing so. This has little to do with the actual cat.