Think the user has to have the mission installed first ,i dont see a way for them to download while playing and it automatically installing , but then saying that i dont have acceleration so i dont have the missions to look through..
sounds like lots of fun if it can be done ,
The start location on the carrier should be a text change or something ,from one player -to two players "multi" but then again im not sure ,you could try asking over at
fsdeveloper