Re: are they casual or deliberate
As you probably know, the European settlers who came to "the New World" were met by people who'd lived here for thousands of years. Many of the words that even we American struggle with are attempts to write the Native American words in their more familiar alphabets. I think I was probably a teenager before I could spell Massachusetts without wondering whether I'd missed a letter or added one that didn't belong.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.