It is hard to learn new theory. I learned that by trying to understand genetics (and physics

). The key is to be humble. Do not make silly comment. Always ask question instead.
Take one question at a time. So, I pick the one with the red text. This one also partially address the silly reply by Baggins.
Check the simple model called "subduction". It said that the heavier crust sinks into the mantle of the earth. It usually takes a few weight percent of water to go down with the rock mass (others get squeezed out). If we calculate the amount of water dragged down to the earth interior, then a question will surface: how could the ocean maintain its sea level through geological time? There is more water recycled back to the earth than the water replenished by all sources we know (include the volcanic water, in case this argument is raised by half-bottle geologist like Baggins). If nothing else happened, then the sealevel should have been lowered significantly since the Pangaea (the last supercontinent) broke up.
This thought does not contribute directly as an evidence of The Flood. But it is an important piece of detail in the model.