I was pretty young on first watch but I do remember thinking she might've been a guest star and this was the end of her run, yes

It’s a bit of a tossup on this one. Main characters don’t die, but Tasha JUST had. Picard and Riker probably had plot armor, but the annoyingly combative older Dr Crusher stand in? It seemed plausible enough.

I remember being freaked out by the realization that I was going to grow old. Like really old, someday. That episode stuck with me for that reason.

However, I don’t remember being concerned because Pulaski’s condition was wrapped up in the “solve” of the episode. If she died it would all have been for naught, and there were so many breadcrumbs in the episode pointing to the super-kids as the problem. Most of the episode is just waiting for them to get on with the solution and dragging out the nail biter as long as they can.

More fatally still, the episode supplies fresh background about the character and especially her desire to serve with Picard – and every viewer of a reality TV show knows that once a contestant gets backstory and calls their family on camera, they’re probably going home that episode.

Sometimes. Getting a backstory can also be a precursor to a character being killed off, like what happened with Gary Mitchell.

Maybe this will just be the season of rotating-door Chief Medical Officers, much like season one had a different Chief Engineer every time it came up.

I saw it as a pretext for Dr Crusher to come back from Starfleet Academy, with Dr Pulaski being her temporary replacement that was unceremoniously left behind on the space station, or sacrificed herself to save the ship. Crusher left just as suddenly (since McFadden was fired), and it wouldn't be a stretch for her to come back.

I don't remember being even remotely concerned. Of course they're going to solve the problem.

I imagine all characters with enough lines having plot armor. So I can be surprised when they are not.