Yeah I know they'r designed to do more some of which u mentioned and more can be found on the websites of the respective alliance websites.
I din know that the alliances buy aircrafts together, are u sure abt that? I mean, the airlines decide which planes they are more comfortable with actually dun u think? How can, for instance, Singapore Airlines impose upon the rest to purchase airbus A380 just because it is? which leaves me to question what the partners are in for when they join the alliances. ie are there any limiting choice making boundaries?