We will be flying to the Caribbean on this itinerary (2 separate tickets):

BHM-ATL
Overnight at airport
ATL-PLS
PLS-ATL
Overnight at airport
ATL-BHM

I have several questions:
Would a gateway hotel be convenient for this route using the Skytrain?

Can I check in at domestic terminal for ATL-PLS?

Does the plane train connect me from domestic to international terminal or will this require a bus?

Is pre-check available at both domestic and international terminal?

Was hoping to stay with the Marriott brand (gateway hotel) unless there is a better option with less hassle?

Thanks for the assistance...