Thanks to MikeZ83 for popping right up with the answer to that poser about Le Var's Reading Rainbow show on TNG: the episode was indeed "Symbiosis," the director was Win Phelps.
But no one ever bit on my "bonus round" puzzle. The sciences bridge stand-in in question (at 1:53 of Part I) was--drum roll please!--
Lorinne Mendell, stand-in for Gates McFadden and often a background crewmember for all 7 years of the show plus Generations... most famously when she got her character name, at least by door plaque: "Lt. Diana Giddings," one of Okona's outrageous new lady friends.
Maybe we'll do another one of these sometime ...