"As in" is usually used to cite an example. When you are talking on the telephone, to clarify the spelling of a name, for example, you can say "SMITH: 's' as in 'Sierra', 'm' as in 'Mike', 'i' as in 'indigo'," etc.
"Mr. Angelina Jolie? As in Brad Pitt?"
"As of" is usually used to indicate time. "As of midnight tonight, it is Winter."
"As of now, nobody knows if he is telling the truth or not."
"As with" can also be written "as is the case with": Writing about someone, just as with/ as is the case with painting, is an extraordinarily
intimate process. (means "similarly to")