New York comic Mark Malkoff decided to test the limits of what an Apple store will allow you to do. Apparently, you can get away with quite a lot, starting with ordering a pizza. (One Apple store employee confronts Malkoff to ask him if he just had a pizza delivered, and when Malkoff admits that he did, the Apple guy says, "Awesome!")
He then tries having a dinner date with live music, and while the Apple store won't honor his request to lower the lighting to a more romantic level, otherwise it's cool.
(There should be a video above demonstrating this, and if it's blank the faults is with the site where it's hosted. I'll see if I can find another source when I get a chance.)
According to another report, an attractive young model -- homeless, computerless, and living out of a suitcase -- was allowed to write an entire memoir of over 250 pages in what I think was the same Manhattan Apple Store pictured above.
Apple Stores are indeed fun places to visit, get technical help (at least if you've made an appointment in advance), or just ogle the new hardware. The only thing Apple stores won't let you do, at least not easily in my experience, is actually buy something. There's no checkout station; you have to intercept an employee of the correct secret caste. I've tried standing around, moving around, jumping in front of employees (who dodged around me like soccer stars in order to reach people who had not been waiting), and on one occasion having tried carried around the goods I wanted to buy for at least 20 minutes finally just gave up, put the stuff back on the shelves, and left. (Of course, as I reached the door someone asked me if I wanted help. I replied that I had, 20 minutes ago, but the need had passed.) Now when I want to actually buy something from Apple I go on line.
(Edited 2016 September 13 to add a note about the missing video, etc.)