I've been thinking a lot about your comments on milk recently. I think you hit on some potential problems with milk (and to be fair, even Peat has an entire article on potential problems with milk, while offering some solutions).
One thing I was thinking about with milk specifically is that it could indirectly cause digestion issues by neutralizing stomach acid. A high amount of calcium (an alkaline mineral) in a lot of liquid could dramatically raise stomach pH, and possibly let a far amount of undigested food travel down the GI track. I think the calcium itself can cause problems in the intestine as well. The worst constipation I ever had in my life was when trying the all milk diet. It happened after a three days on the diet, and without going to TMI, I was getting worried I might need to seek medical help. Thankfully, it resolved, but was a worrying episode. I took three long acting oxycodone tablets over 3 days after a surgery, and while they where also a bit constipating, it was nothing like the milk diet attempt. I did discontinue them, as I got no pain relief, and didn't want to tempt consitpation further.
I would think yogurt and kefir could also cause similar GI issues, but that might be more to do with higher lactic acid content.
Regardless, I'm dropping most dairy (save butter, cream, and some cheese) for a few months to see what happens.
Sounds good man, let me know how it goes.
As for your calcium statements I used supplemental calcium for a while (calcium carbonate) and it actually causes some digestive issue for me that I attributed to a buffering of stomach acid. I was taking the calcium in juice during my meals to try to balance out my calcium:phosphorous ratio. So basically I agree with your POV.
I've mentioned this before but I also got very constipated on the milk diet, even with A2 milk and goat milk. I used quick acting oxycodone after I had my gallbladder removed, only 1/2 a tablet one time, and it constipated me for 2 days. To be fair though I think my body is very sensitive to opiates, even the opiates in rice produce a noticeable effect for me. I think other peoples mileages with these foods may vary.
Yogurt and cheese are almost all casein. They actually have the strongest effect on me, opiate wise. I do love cheese tho, its the one food I would add to my diet if I could tolerate it better. A nice pecorino romano and an aged cheddar would be nice. I'd be eating cheese steaks (cheddar cheese melted on a flank steak, no bread of course) everyday. My boy eats cheddar cheese omelets everyday and my envy is real strong lol.