I question these assertions:
"1. An average surface temperature for a planet is perfectly well defined with or without rotation, and with or
without infrared absorbing gases"

"4. The only way the fourth power of the surface temperature can exceed this limit is to be covered by an atmosphere
that is at least partially opaque to infrared radiation. This is the atmospheric greenhouse effect."

For instance, if Earth had say 1/billionth of the water in has, what would it's average temperature be?

Say, it started with same greenhouse gases and same atmosphere that it currently has: same CO2 levels, water vapor, 1 atm of pressure of roughly 20% Oxygen, 78% Nitrogen, cloud cover, etc. Ever thing is the same, ice caps at poles, same amount of vegetation, but obviously where there is now currently vast oceans of water, make it oceans of mostly sand.
Can it be predicted if earth would warmer or colder or about the same?

And wouldn't there been difference if you measured global temperature from the bottom of our ocean basin as compared in the higher plateaus which we now call continents.
In other words do want to measure mostly in the Atlantic and Pacific basin which are about on average more than 10,000 feet below our current sea level or measure where we currently measure land temperature or both?

In other words, I'm trying to make this as simple as possible. Our current Earth has 1.37 billion cubic kilometers of ocean, so leave 1.37 cubic kilometers of "ocean". Or maybe leave 100 cubic kilometers of "ocean"- point is there wouldn't be any oceans and it would be replaced sand dunes some salt seas, and rivers would flow from the current land masses and eventually evaporate.

Let's try something different but along these same lines.

We going the change Earth even less than above.
We going wall off a fair large chunk of the Ocean. It will be a circle 2000 miles in diameter with say Hawaii at the center of this circle, the line of the circle will the mass of mountain ranges, and be say a couple miles wide at the top.
Then drain the ocean inside the circle.

Will there be a temperature change for those living on Hawaii- will it get warmer or colder or about the same? And what will the average daily temperature be on the ocean floor now that all water has been removed?