I always pay addtl for EBCI, just so that I don't have to worry about checking in. I have always checked myself in when flying home, regardless of the airline. There is no way that I'm letting someone else do my check in, especially at the 24 hr window! Others may have different experiences.
I always check my bags with RAC first thing in the morning when flying home later in the day. I try to get down to the RAC counter by 7:30am, otherwise the line can be on the long side. Then, I go about having fun on my last day, returning to my resort about an hour or so prior to my stated DME pickup time. That way I have plenty of time to use the restroom, get any carry-on bags out of storage, check out the gift shop one last time and be at the bus stop 15 mins prior to p/u time.