Shakespearean English isn't the same as modern English, and native English speakers don't get all the word play (unless they've studied Shakespeare), so don't judge yourself based on that! But I too got to see David Tennant in Much Ado, and he has a gift for conveying the sense of the Shakespeare even when you don't quite understand the phrases. I too love David's voice.

I've heard "pleased as punch" before, so Sean didn't invent it. In fact, it might be a little more common here than "proud as punch," but both are around.

I love your video! I'm from California, so I really enjoyed watching what you did on your trip here. And I had no trouble at all understanding your accent. Your spoken English is great. (And I know it's harder to speak than write a foreign language!)