General :: Stop Apps From Starting Automatically / Overriding App Permissions?

Some backround on this post. I own 2 android devices, a Samsung Galaxy i9003 and since yesterday, a Nexus 7.

I have ditched my Galaxy as a phone and gone to Blackberry due to battery issues, and apps on my Samsung draining the battery from full to empty in the space of a few hours, so I am now very careful about what I install. Since removing almost all the apps (and the SIM card) from the galaxy, I now have a battery live measured in days (including watching video) rather than hours just sitting doing nothing...

I understand the use of apps auto-starting themselves to provide notifications, such as Facebook, Twitter & Accuweather, but even though I do use these apps for what they are, I do not need them running all the time to provide a notification: The added "work" in starting the app to check updates is worth the extra battery life I get, as if I leave things alone to be automatically managed, my battery life is divided by 10... and having to flip the phone in and out of flight mode is a pain... (especially when you forget to activate it in the afternoon after charging and at 3 AM in the morning you have no battery left to call a taxi...)

So, what I would like to understand is this: Where does android store the information on autostarting applications? Even if I use a task killer, some apps will restart later on. Android must have some sort of task scheduler to restart registered apps after a certain amount of time has passed or on certain events.

how Android manages this list - and more importantly, how to change it, and also if there is any way to override the registered permissions of an app once it has been installed?