You say, [LIGHT goes through the atmosphere. It hits the ground and is then converted into heat. Heat is a different kind of radiation than light.]
But what IS heat, actually? Heat is a "radiation"??
Let's look at an online dictionary definition
a. A form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction, through fluid media by convection, and through empty space by radiation.
b. The transfer of energy from one body to another as a result of a difference in temperature or a change in phase.
So it looks like you're not quite on target with your explanation. Heat (apparently) is NOT a radiation but rather ... a condition -- a "form of energy ... associated with motion of atoms or molecules." So if there are no atoms or molecules for light to strike, there will be no manifestation of heat.
You might compare this to a car going down the road at 90 mph. As long as the car doesn't strike anything, there will be no "accident". But as soon as it strikes something with significant mass ... there will be the manifestation of accident to the degree of the mass and solidarity of the mass. Will this accident then "radiate" anywhere? Well it might ... depending on whether drivers and passengers are still able to move. The point to remember though is that any activity ensuing AFTER the strike is merely secondary to the energy of the strike itself -ie- the car hitting a concrete barrier did not CAUSE the ambulances to scream down the highway or the police to arrive in droves or the many emergency bodies to be running around all over the place picking up stuff.
You go on to say, [So when the ground reflects that heat back up toward the sky the CO2 in the atmosphere traps that heat and keeps it in.]
The ground can't reflect heat. The ground gives the MANIFESTATION of heat via increased atomic/molecular activity from being hit by light ... and then SETS UP its own radiation (or vibration in the form of infrared light radiation) ... which then goes outward in all directions -most of it out into the "sky".
Phred-> [And guess what? CO2 traps heat.]
That's true ... but in WHAT WAY?
A thick blanket of CO2 surrounding an object will act as an insulation for the object ... largely PREVENTING the escapement of heat from the object. CO2 has a much greater capacity for insulating than our own atmosphere of Nitrogen(70%) and Oxygen(20%).
But we're talking about a true blanket on Venus ... which is almost 100% pure CO2 vs. the earth's atmosphere which contains only .038% of CO2.
What happens when you pull a blanket apart into tiny pieces and then use only tiny pieces -maybe every 6"- to cover a body? Suppose you pull a wool blanket apart into tiny pieces and then cover your body with .038% -(that's PERCENT! In real ratio, it's .00038 or 380 parts per million!)- of your body surface area ... with microscopic wisps of wool...
How much warmer would you feel?! How much warmer would you feel on a cold night, under this kind of "insulation"?
Phred-> [Venus' atmosphere is 92 times as dense as the earth's. And it is almost ALL CO2. So any light that goes in hits the ground and turns to heat then STAYS there.]
True enough ... but how much light actually GETS to the surface of Venus? Since there's a hefty layer of SO2 atop the CO2 -and SO2 is a reflector- it's extremely DARK on the surface of Venus. If it's dark on earth, we know what happens: it gets COLD. Same thing is true on Venus. If it's very dark on the surface, the sun's rays aren't getting down there and therefore it should be COLD on the surface ... but it isn't. What makes it HOT on the surface?
Phred-> [The heat generated from the volcanoes is infinitesimal compared to the heat of a star 30% closer to venus than it is to the earth.]
That might be true but if the sun's potential heat is being reflected OFF of the planet via the massive SO2 reflective covering ... it can't get down to the surface of Venus to contribute any heat to Venus and so ... something else has to account for the very high temperature of Venus. What might that be? A nuclear reaction heat engine inside of the planet.