not quite... it's that bad/good money doesn't have meaning until you're comparing it with some objective third thing... in the time periods where Gresham existed, and where the Law would apply, you have bimetallism i.e. there's a fixed ratio of gold to silver.

Meaning, there's an incentive for you to pay with the "cheaper" metal since one is always undervalued relative to the other since world market prices of gold and silver always move.

There's no such mechanism for bitcoin so the concept doesn't apply. That you spend CCs first because they're less money-like than sats says nothing about good/bad money.

No, they coexist; and relative prices adjust