Just returned on Monday- my son's team was participating in the Disney's International Salute to Baseball July 6-13.
Is there a website for the particular event you are participating in? I found a lot of my answers there. I can tell you what our experience was but don't want to steer you in the wrong direction in case the rules are different. I'm happy to answer any questions about the complex that I can, though!
For my son's event- all players were required to stay on site, and the only options we were given were All Star Sports and CBR. We all stayed at CBR. There were a few kids whose parents still decided to stay off-site, and the kids had to pay for their spot in the room whether they stayed in it or not. It was part of a package- their ESPN credentials (or event pass for spectators), the room for a minimum of 7 nights, a ticket to an exclusive after hours party at Typhoon Lagoon, and the minimum ticket purchase which was a 3 Day Park Hopper. This was under $600 per person, so still a great deal. It worked out great for my family of 5 because 4 of us stayed in a room and DS stayed with his team mates at the same rate.
Yes, it appeared as though the only shuttles to/from ESPN WWOS were for those hotels. There wasn't a huge lot, but they had a lot of overflow parking set up in the grass for this event, as well as the AAU Girl's Basketball tournament that was going on at the same time.
Another head's up, for those that didn't purchase the package, the length of event passes for Spectators to get into WWOS was $80/pp and the TL party tickets were $55/pp.
My family at at the ESPN Grille a few times- it was actually pretty good for counter service, and they have the Coca-Cola Freestyle machines. It also has a full service bar, but we didn't have time to hang out there!