I don't have the official answers to these but the Airport shuttle is included to the Wildwood hotel. If you stay at another place you have to check with them. I know the Pokolodi where I stayed in '07 had free transfer. The airport is not far - maybe 20 minutes?
Most people do get there early - at least to ski Sunday. That is definitely recommended if you can do it. There's fewer who stay after, but they're there! Also, many ski at places 'nearby'.
There's a free shuttle that connects the ski areas - Aspen, Aspen Highlands, Buttermilk, and Snowmass. I believe after 5pm? it costs a couple of dollars. Those shuttles work quite well, and when we went to Aspen I had the option of staying and blathering endlessly at ski shops. Then I just got on the bus back to snowmass.
All in all those areas are fabulous and it's amazing that they are connected by a bus system that actually works well! At snowmass there's a small village you can walk around and at the end of each 'street' is a ski trail that takes you to the lift. Cat tracks or similar are recommended for walking in your ski boots.
Snowmass is a great area - probably overall the best for this event because of the variety of the terrain. Aspen has a different look to the mountain - steeper, a little more rugged. It's a great mountain and all the hype overshadows that. Really, it's almost small by western standards but that allows you to feel right at home.
Aspen Highlands. The Highland Bowl there is definitely one of the greatest places in North America. It's not the biggest, the hardest, or the best, but it's probably the finest single place. Really, you have to go there. I only skied there once and I feel that way about it!!
The Highland Bowl is sort of like Venice, Italy - you've got to go there and you'll never forget it. I think Napolean called Piazza San Marco "The finest drawing room in Europe". That's what the Aspen Higlands Bowl is to skiing in North America.
Here's an amazing short film I found on the internet. The skiing's nothing to talk about - just three people having fun on a nice day! Overall it's one of the best short films on rec. skiing I've ever seen. The film definitely conveys the feelings people have about the Highland Bowl and skiing in general.
If you have the opportunity, you really need to take it and go there with people who know it. Definitely go to snowmass esa!
(won't be able to respond - leaving for Stowe!)
(note to mods: feel free to move post to whatever esa thread you want)