If I could make a suggestion...um, it might be to your benefit to make it clear that you're talking specifically about PX Marts in Taipei - as opposed to supermarkets in Taiwan (or anything) in general, becuz a certain grizzled crocodile is going to pick apart the transcript and say, "Yo, wait a minute. I buy the six-pack of Kleenex toilet paper rolls at my local" E-T-C. I realize you're not doing this for the crocodiles, but that never stops them from surfacing with a red pen.
For instance, in #5, you say:
In most PX Marts - I haven't been to every single one since the buy-out (locals are calling them I-Mart now) - you are correct. Booze choice is uncomfortably limited. The key is that you said "in this grocery store". As you mentioned in passing, there are a bunch of supermarkets in Taipei that are at least in the same ball park as the average low-rent Safeway in Fresno.
So basically, all I'm saying is perhaps it would help to be more specific, all the time. Sweeping generalizations are a vulnerability. You probably don't want to deal with dudes like me who won't hesitate to challenge them. There's no question that many of your observations are - or, would be - on target, if they were focused laser-like on a specific difference.