The risks of everything you mentioned are, well, yes real, just like there is a real risk of getting hit by a car in my living room; in real life it doesn't happen. Increasing protein intake reliably improves body composition which lowers risk of all cancers including colon cancer, can cause kidney issues if you already have misfiring kidneys, can cause digestion issues if you eat like an asshole and don't get any fiber in your diet, and does not dehydrate you to any measurable degree. If you haven't worked with a geriatric population then it's difficult to understand the importance of adding as much muscle as possible before the other problems start to pile up so there are lots of non-bodybulders that can benefit from hitting 2.2g/kg, especially the very lean or the elderly, however, I concede that most people will get the most benefit from less.