I think there is too much emphasis on keeping shoes dry. The only time I was really worried about keeping shoes dry was in the winter when there were no stream crossings (everything frozen!).
Even when I wore huge clunky leather mountaineering boots, simply slogging through snow early season meant boots were always wet anyway. Just be sure to open them up at night so when frozen in the morning, you can still stuff a foot in. A short time of walking will warm both your boots and your feet. Now, with light hikers, they actually dry as I walk and although somewhat damp at the end of the day, they are not soaked.
I take socks off, unless a wide glacier fed or snowmelt fed stream where I prefer the warmth of socks. (If I know I will be doing a lot of crossings I take one more extra pair of socks- only a few ounces. ) I do take out insoles. My hikers fit so that I can tighten them up fairly snugly to fit without socks. If I anticipate a lot of moderate wading, I will take crocks or other water shoes. If I want to save some weight, I do not. My hiking shoes are comfortable all day. No need for camp shoes. I would never take Crocks simply for camp shoes. I would say that I do not take extra shoes in the Sierra most of the time, whereas, I always take wading shoes in the Wind Rivers.
I have had days upon days of wet feet and never caused a blister. I sleep barefoot at night- I think that helps. At least my feet are dry for 8+ hours each day. I know you can get "trench foot" if your feet are constantly wet for weeks on end.
Each hiking area, each trip, each person, will have different requirements for stream crossings. There is no one answer. Some with tough feet can go barefoot. My feet are so tender that I do not even go barefoot across a sandy creek. There always is the danger of cutting your feet.
There are a few cases where you could get a boot wedged under a rock and then drown. This happened years ago on the Green River. After this event, NOLS did not allow students to wear boots in a canoe. You really should have special boating shoes if you canoe or kayak. With boating shoes, you can slip a foot out of the shoe if it gets stuck in rocks.
However, the probability of wedging a shoe, is less than falling due to instability with Crocks. But, if you do wedge a foot (which can also happen in any shoes, including Crocks) and the current pulls you under, you are dead.
Really difficult crossing should not be done solo. With a group others can spot you, or at least retrieve your pack as it floats down the river. Plus there are arm-lock methods for groups that allow the group to cross more difficult water than a solo person could.
It is generally thought that undoing the waist belt and sternum strap is required. Yes to the sternum strap, but at times I have kept the waist belt clipped for added stability. My waist belt is pretty easy to unclip. The trade-off is less probability of falling in vs. a small chance of not being able to undo the strap if I do fall in. By the way, if you go into underbrush or trees even with waist strap off, you could still snag the pack and not be able to get free from the shoulder straps.
Stream crossing is one activity that it is advantageous to be tall and heavy. I am short and light so am more limited to what I can safely cross than most. Once you get over crotch deep it is hard to keep foot contact with the streambed.
Also note that tying a rope to someone who is crossing is not a good idea. If they fall the rope simply pulls them under. However, hanging onto an upstream rope sometimes is helpful. If you fall you simply let go.
Sorry that was so long. There simply are no set-in-stone "rules".