I understand too, and have experienced mild headaches when I detox from it. I don't even drink that much (a couple espressos a day).
There is also a condition some folks have (can't recall what it's called) that escalates as they continue drinking coffee. It's accumulative, but dissipates when you stop drinking. I have it, and can start feeling ill after a couple months, especially if I'm drinking a lot or if I over-roast my beans. Burnt beans really seem to bring out the issue.
Starbucks is known for caffeine, so you might notice a nice improvement just by getting a better coffee. Home roasting is a fun hobby, and might help. It'll certainly help with quality. You might consider more time-consuming methods of brewing too, which will force your to slow down your intake. I make lattes, so it takes a few minutes of devoted time for each cup. This generally keeps me to one or two cups a day, which is quite manageable.
From your articles, it sounds like you might have a solution anyway. But I figured I'd throw out a little of my own experience, in case it's of any use. :)