I'll be glad to address your other point but let's get something straight first. I *do* understand how it works. Please answer this question. If you have a well mixed gas containing A and B and if you add energy to A by some means like say shining a light on the mixture that A absorbs and B does not, do you think some of the heat added to A will be communicated to B or will the A molecules retain all the heat?
I said it did.