I have a question. When topping sealant with carnauba, I would need to wait for the sealant to cure right? I guess 24 hours should be ok.
You'd have to wait 24-36 hrs. Make sure to QD the surface again before applying another coat of wax.

After this, how should maintenance work? Just carnauba again every two weeks or should I do the whole shebang again? (Polish then sealant then carnauba again)
Sealant should last a couple of months, so you can wax around twice a month or more depending on your mood and free time . Then apply sealant once every 2 or 3 months.