Not sure... i read somewhere you are ok with any and all upgrades as long as the original apple ram is still in place somewhere. Not sure if that is true or not.
No, RAM is one of the things that is defined as user upgradeable in the macbook, along with the HD. Now if you damage anything during the upgrade, they will not cover the damage.
On that note...when I was lifting the RAM cage 30 degrees I hairline fractured it. RAM operates fine but I was wondering if I could pay to get this repaired and still be covered by AppleCare?