No system is a closed system. In simple terms, the more CO2 you have in the lower atmosphere, the more difficult it is for that energy to escape. The energy will eventually escape, it’s just that it takes longer. I don’t think you actually understand thermodynamics. As to water, water vapor as a global percentage of atmospheric constituents is relatively constant, so no, water is not the cause of increased trapping of thermal radiation. There is no evidence that solar output variations, which are very minor in how much energy reaches the Earth, plays any great role.
I think you grossly overestimate it, and greatly underestimate the trillions of dollars that the fossil fuel industry represents. As to you claim that scientists only get funding if they investigate AGW, that’s like saying cosmologists only get money if they investigate Big Bang cosmology. Since AGW is completely non-controversial in the climatology community, it is as much a feature of climatology as Big Bang cosmology is a feature of cosmology, General Relativity and quantum mechanics is a common feature of physics.
Look, think of the atmosphere as a big tub. Let’s imagine you fill that tub half way with water. You have 2/3s" hose feeding the tub, and an equal size hose draining the tub. Providing the volume entering the tub is the same as the volume leaving the tub, you have the equivalent of thermodynamic equilibrium.
Now, let’s imagine you replace the drain hose with a 1/2" drain hose, and yet the hose feeding into the tub remains a 2/3"s inch hose. This is disequilibrium. So what will happen to the volume of water in the tub?