You are not hallucinating. The ABC Star Trek II broadcast did include some previously-cut scenes, as well as different edits. (I believe I still have the videotape, though it's old enough that the picture may have degraded significantly.)
For example, in the theaters and on home video the Kirk/Saavik turbolift scene was one continuous master shot with them at opposite sides of the screen. The ABC broadcast intercut closeups of each character instead. And, yes, when Kirk was piped on board the Enterprise, Scotty introduced Peter Preston as his "sister's youngest, crazy to get to space."
Vonda McIntyre's novelization of Star Trek II, as with her other novelizatons Star Trek III: The Search for Spock and Star Trek IV: The Voyage Home and the "origin" novel Enterprise: The First Adventure, restored the "cut" material, including references to Saavik's Romulan heritage and Sulu's promotion to captain of the USS Excelsior. The latter was actually filmed but left on the cutting room floor; according to his biography George Takei suspected that William Shatner didn't care for the scene and intentionally didn't play it well.
"I do hope that Paramount at some point revisits this film (and all the Trek films) with a DVD special edition. I've got a VHS, off-air recording of this film, as shown on ABC more than a decade ago, and there's some cool extra and extended scenes that I'd love to see in DVD quality. In talking with the studio, I think there IS reason to hope that this might happen in the next few years. In any case, I'm pretty thrilled with this disc as is."
-- Bill Hunt, www.thedigitalbits.com