These issues seem sort of subtle, so I think you should just continue treating these regulars nicely and hope their attitude improves. Maybe regular #1 has seasonal depression, or there's something else that made him act like that.

As for the others... what kind of adult complains to the shift that their name is spelled wrong on their coffee, and has it remade? Seriously, it's a damn cup of coffee.

Regular #2 isn't much better, but you can just ignore her frostyness. Just imagine her, in all seriousness, complaining to her family and friends about how her order was rung up wrong. And if they're all acting different, I bet she embellished the story a little. Either that or they're all like her. But it doesn't really matter either way.

When a customer throws a fit over a simple mistake like that, they're acting like a child. Some people will judge your entire character because you caused one inconvenience to them. That's just how people are, unfortunately. Don't take it personally.

Honestly, if you try to analyze every customers behavior and attitudes you will drive yourself insane. Most of the time the attitudes of others are about things completely unrelated to you, and are totally out of your control. All you can do is do your job to the best of your ability, and keep showering them with great customer service.