Quote: "...and Steam says that I cannot sell games made on AppGameKit"
Was that in their terms of use, or a direct communication with you pertaining to a specific release of yours?
This is disturbing indeed, and a direct quote (without your game specifics or entire communication with them) would be appreciated.
I have yet to develop for Steam, but a friend is suggesting that I do. (I am now at a point to give it a try)
However, if Steam has taken some new stance on rejecting AppGameKit, then that would force me to reject them.
Quote: " ... point A / D / G."
That terminology is confusing for me, so can you/someone please explain that?
Quote: "
Question: Can the games created in AppGameKit be sold or not?"
YES! You can sell your games made with AppGameKit, however...
if you are choosing to use a third party distributor,
then you have to abide by their terms for their distribution platform.
That has nothing to do with the
permission from TGC for you to distribute your games made with AGK.

Coding things my way since 1981 -- Currently using AppGameKit V2 Tier 1