Trust me, we use the app all the time and none of us would want it to autoshare.
As for the particular permissions, they all support the basic functionality of the app.
We need your basic info so we can set up your name/picture in your profile
We ask for permanent permission so that we can keep that up to date.
We need to be able to access your friends information so that we can help you find people to follow in the SocialCam.
The reason we ask for each is pretty straightforward. Facebook doesn't have a particularly granular permissions system, so even though we don't use "current cities of your friends" we get it anyway.