No, that has mud in it that takes days to settle out of still water. And consists of multiple layers, here is an example: a clayy limestone (with rare dinosaur bones) at the bottom, a very hard calcitic limestone in the middle, and a shell-sand on top. The middle layer had to turn into limestone before the top, because percolating groundwater is by far the most common (and fastest) way to turn shell-rich sand into limestone (and thus, deposits tend to turn into limestone top-down).
And have personally observed exactly the same patterns.
Yes, but not often: Glycymeris americana is incredibly common (I probably have about 20000 of them) in the recent down to the Waccamaw, but is non-existent in any lower deposits. Chespecten is large and common in the Yorktown, but is unknown in any deposits above it. Global planktonic foraminifera are even more specific, and are a standard way of correlating faunas across basins.
No, they aren’t exactly publicized widely (or easy to find), but as an example, Creseis shells are needle-shaped and will break if one sets one’s finger on them (they are pelagic, so a strong shell is not that important). Most shells on the beach are broken, and many of the ones present (busyconids, Mercenaria, etc.) are very sturdy shells.
And the problem is not sediment going on top of them, the problem is water transport: if there is much of any current where they are, these things will get picked up off the bottom, banged around (and destroyed in the process), and then set down.
As I have said, most of these deposits contain more than one of the following: distinct layers that had to finish being deposited before the next one started, mud that requires very still water for a long time to settle, and fragile shells or mold of them. None of those can be deposited rapidly.
Radiometric decays release energy, if the rate of decay goes up a lot (and nothing else changes), then the amount of energy released would as well. That energy is going to mostly (since it is inside earth) end up as heat, and if one works through the rate of decay needed:
That problem can be fixed by decreasing atomic binding energy (which would increase radiometric decay rates and decrease the decay energy at the same rate), however, the binding energy would have to decrease so much that atomic nuclei would get ripped apart by the repulsion of the protons.