We will be sailing the Elation for the second time Jan 6. The last time we used the shuttle bus that Carnival sells for about $15.00 pp. We will probably do that again this time.
Boarding time is more or less set on the arrival tme of the ship
that morning. If it is late you will be processed but not boarded. I haven't heard of any early boarding unless it an option on the class 11/12 suite.