“take another tact” — it’s tack, from sailing ships
“baited breath” — nope, it’s bated, meaning roughly “held back”
“must of” — it’s “must have“. And a huge collection of related phonetic spellings of mumbling passed through a spellchecker.
I, of course, find myself making some of these now and then myself; that’s the most annoying thing. I say they’re just typos when I make them, and you can’t prove I’m wrong. Nyaaah.