The key line in "I would not have it grow on my chin" is neither "chin" nor "my", it's "grow".

If she emphasizes "chin", then she's implying she wants it to grow somewhere else... but wouldn't she already have that "beard"? If not, then she's prepubescent, which introduces a creepy note that doesn't work with the sweetness and light of the story. If she's prepubescent, then so is her twin Sebastian, and are we really expected to believe that Olivia would fall in love with an underage boy?

If she emphasizes "my", then she's saying she wishes it would grow on someone else's chin. But... in that case she's sick for a beard that doesn't exist. Makes no sense.

If she emphasizes "grow" then she brings into question what else a beard could do. It could rest on her chin. If she emphasized both "grow" and "chin" then that beard could do anything at all, and the more childish minds could still have their dirty joke.

But really, I think trying too hard to make Shakespeare transgressive (it's secretly gay! no, it's transgendered!) is just as silly and childish as bowdlerizing.

Shakespeare threw in a filthy double entendre whenever possible. You don't have to force it, just let the Bard be his pervy self, and enjoy.

Huh? Viola is sick with love for Orsino. Orsino, like most men of the time, wears a beard.
As with many "ambiguous" lines in Shakespeare, there's no mystery if you read the play.

Absolutely. There's plenty of unambiguously bawdy lines in Shakespeare. This is not one of them.

Hamlet's "Did you think we were discussing country matters?" emphasizing the first syllable of "country" is another notoriously oversexualized line.

Not unambiguous. Shakespeare was writing for drunks and revellers. Anything that sounded kind of dirty reeled 'em in and kept them in thier seats. Shakespeare was great. You don't have to make it dirty, but like any Will Farrell movie, it doesn't hurt if you CAN make a sex joke out of it.

Maybe it's ambiguous. Maybe not. You could, reasonably, see it either way. What's the word for that...?