If you are staying on Disney property you can use ME to and from the airport regardless of which airline you are using. If you are staying at one of the value resorts, you can use RAC (there is a trial at the values that has been going on for quite some time now). Upon you arrival at MCO, ME will retrieve your luggage and deliver it to your room and that doesn't depend on the airline. If you aren't staying at a value resort (or choose not to use RAC), you will have to bring your bags to the ME bus for your return to the airport and you will check your bags there. To check in with SWA for your return flight you have several options. If you have a web enabled phone you can go to mobile.southwest.com and checkin. You can go to the concierge at your hotel or guest services at the park and they will check in for you. Of course, if you have a laptop with you, you can do it yourself. If you have a friend/family member at home that you trust to do it for you, that's another option. Or you can purchase Early Bird Checkin from SWA and you will be automatically checked in. Hope that helps.
