Hm, that's pretty interesting. The phosphorous:calcium ratio problem that your link addresses (too much phosphorous in the blood leaches calcium out of bones and into blood to maintain the proper ratio, this leads to weaker bones and additional calcification of soft tissues) brings to mind the problem with salt; it's not that additional sodium intake is necessarily unhealthy, it's that too much sodium can throw off your sodium:calcium ratio which can then cause the same kind of problems (plus higher blood pressure depending on the person and just how much sodium they're taking in and are able to process). Not something I'd heard about before.

I did some reading after you mentioned risks of high protein, and while I didn't read about calcium I did read about cancer. More protein means more cellular growth and division, and more cellular growth and division means more risk of cancer. This, also, becomes more significant in older people.

Seems like the best plan is to eat your protein and build your muscle when you're young and then cut down when you get a bit older.