So can you explain how huge numbers of layers form in one single event, and why the layers look different around the world when it's supposedly a global event?
The flood lasted many days and it has different water sources, the rain and the flooding water from the "fountains of the great deep". Rain would have done different layers, depending on the place and what materials there were. And the water from the fountains carried different materials and its effect was probably more dramatic, because it was more powerful. The water from below would also probably have had many minerals in it to cause different layers.
And, by what is said in the Bible, in the beginning earth was covered with dust. I don't know what exactly it was, but what would have been carried away from the fault line of the original continent, for example Mid-Atlantic ridge, cleaning the are that is now for example the bottom of Atlantic ocean. By what we can see from the result, the conclusion is, earth (=dry land) was not homogeneous before the flood.
drowned birds, dinosaurs or extinct mammal species would float just as well when their bodies bloat with gas during decomposition. Or get eaten (by whom, though? Because everyone is dying??).
Eaten by water animals, and birds that can live on water.
It may be that dinosaurs had died before the flood already. But, on basis of their structure, I would think they would not float when dead.
And many birds could have drowned, but because they normally can fly, they would not get as easily stuck into the sediments. They would fly some time and drop to water and sink. But at that point there would not be much material coming to cover them and make them fossils. They would sink to the bottom of the ocean floor, where they would be eaten by all kind of water animals.
NATURAL heating. As would be created by continents moving rapidly across the earth, by limestone as ist forms, and most importantly: by the decay of radioactive isotopes.
Why do you think they moved rapidly across the earth?
I think Bible suggests that the original continent was broken and sunk down. And it was relatively slow process, almost a year, because the water below it made it softer.
Many vast limestone formations were likely from the dust that covered the earth in the beginning and were carried by the flooding water to current places.