I doubt, though, that the concept of Pike making a complete 180, embracing illusion and sacrificing reality (not to mention providing the Talosians with the slave race they desired) was really intended and planned for - it just happened when the writers threw together this mess, a clip show among the innumerable clip shows of the modern TV world. Were those less common back then?
I don't think radiation-burned Pike and post-menopausal Vina would produce any children for the Talosians. But you have a point about the framing story undoing the themes of "The Cage."
Maybe they should have done a traditional flash-back episode where let's say Jose Tyler or Miss Colt visits, and Spock says "Remember when..."
More artfully than that, of course.