If Apple's Black Friday promotion turns out to be not compelling to shop there, if I buy a MBA at Best Buy, Target or another retailer having a big money-saving promotion.... 1. Will the Apple Store's Genius Bar still service my MBA even though it were purchased elsewhere? 2. Do these other retail stores also sell AppleCare and, if so, would any offer discounts on Applecare? 3. Can I still buy AppleCare at the AppleStore at a late date even if I buy the MBA elsewhere? Thanks.