did somebody watch LotR high as a kite

When a "period piece" opens with "We Will Rock You", they're letting you know up front to turn your brain off. I appreciate them for it and loved the movie.

It's basically the entire plot of A Knight's Tale, a 2001 movie that I happened to rewatch like two days ago lmao

I realize someone already answered you, but just to further clarify: astrology was a common literary theme during the English Renaissance. Probably the most famous example modern audiences would be familiar with would be Romeo and Juliet, the "star-crossed lovers."

Stars signify destiny and birthright, so if the young lovers' stars are crossed, they're not in alignment and their union is doomed to a tragic ending. If one of them could've "changed their stars," Romeo and Juliet might've had a happy ending.

One can do an impersonation "truthfully", in the sense that everyone is aware it's an act. See: Elvis performers. I believe the phrase falsely impersonate is to imply that you were employing an impersonation under false pretense, i.e. someone assumes you are someone else and you play into that misconception.