This is a good review. Something to keep in mind though - when you start with good quality coffee beans, you're not likely to end with a bad cup (unless you just burn the coffee while brewing it). And the reverse is also true - if you have a poor quality coffee, there's nothing you can do to make it taste like a premium one. The GIGO concept applies to real life.
Regarding acidity of coffee:
I can't tell you the exact figures of different coffees, but in general, the acidity levels are higher than fruit juices, tomatoes, beer, and sodas by a pH level of around 2. Coffee is generally lower in pH than saliva, but higher than any of the other things mentioned. It may not necessarily be coffee that causes the acid reflux and indigestion, but bad coffee instead. If you drink most coffees off the shelf at your local grocery store, you're likely just drinking bad coffee - low-grade, over-roasted (burnt), likely stale.
Anyway - good post. If you're a fan of coffee, you should check out my "blog." I work with coffee farmers and have been writing a series on it. It'll give you some insight into the quality/producer side of the industry.