I'm pretty positive you can still purchase Apple Care even if you buy the computer from Best Buy, I think up to a year after (btw, a student discount applies for AppleCare as well). Also, for an even slicker deal you can apply the student discount coupon from Best Buy to take off an additional $50 ultimately yielding a $2,299.99 price.
Return policies have returned to a 14 day policy. They have a no question asked return policy as well though they will ask you generally what is wrong with it for example if you do decide.
Unless you have elite or elite plus membership, that return policy extends 30 or 45 days. Any problems you have with returning shouldn't be any different from any other place so long as you don't break or damage the item. Any differences should be attributed to the store's possible stupidity or incompetence.
As much as other people hate BBY, I believe there should be nothing stopping you from buying it from them. If you dislike them that much, ask Apple to price match.
Yes you can still get Apple Care on a computer you buy from Best Buy. I did it last year.
I still don;t get the Best Buy hate. I buy a ton of stuff there and have never really had any problems. Fair prices overall, great price matching, and the rewards program is nice too. Sure they don't always hire the most knowledgeable or helpful people but; that's retail and most of us know what we want/need and the specs of whatever we're buying. Seems that is a nonissue.