My model has it raining (water running down drainages into the sea) but causing no large flooding (although there might have been flooding in catchment areas). The benefit of such a rain for Noah would be to swell the wood of the ark to a watertight condition (absolutely necessary; ask any wooden boat owner), and, to provide a supply of fresh water for the ark.
You are still ignoring both what the Bible says about the characteristics of the Flood and the scientific evidence we see.
A slow upwelling of the ocean floors, much like the lava domes that form in volcanoes, would spill the sea waters onto the land, much like a tidal surge. As the water deepened the continents would begin to sink under the weight (the earth's crust is quite flexible). This would accelerate and expand the floods reach over all but the highest mountain peaks.
You need to give some evidence that continents can sink under the weight of water. After all, continents are just the highest part of continental plates. The water is already sitting on those continental plates and they don't seem to be going anywhere.
There is more than enough water in the seas to flood the entire earth.
Not to the depth you need. If the earth were a perfectly smooth sphere, and using the available water we have right now, the planet would be covered by a layer only
~1.6 miles deep. Not anywhere near enough to cover three mile high Mt. Ararat.
When the sea beds returned to their normal state the flood waters would return to the sea from whence they came. No mystery here.
The deepest seabeds are 36,000+ feet deep (Challenger Deep). For them to rise up to evenly distribute all the water all over the planet, and then sink back down again enough to leave the continents dry again, in slightly less than a year, would cause such massive tsunamis that nothing could survive it. We're talking tsunamis at least 1000s of meters high, if not more.
The Amazon River basin sinks about 4 inches under the 80 or so feet of annual flood water. What is actually happening is the sagging river basin crust is being held up by the unaffected dry area around it. If the floodwaters were broad and deep enough whole continent would sink.
One, I would still like to see some evidence of the Amazon River basin sinking.
Two, if the ocean depths have leveled out and the water is all over the planet, the continental plates won't go anywhere. Think of it this way, if you take an egg and completely surround it with your hand, then apply pressure evenly all around the egg, you won't be able to break it. The only way you can crack it in this situation, is to put sustained pressure at just one point, which you won't have your flood scenario.
Picture a desktop globe. All it takes is a slight deformation, about the thickness of 2 or 3 sheets of paper, to cause global flooding from the oceans on the actual scale.
Which
will not give you enough water to flood the planet to the depths necessary to cover the mountains of Ararat and
will result in massive tsunamis and heat from the rapidly rising and falling continental plates that you are proposing. This will not be the gentle event you are proposing.