Good metaphor, particularly for Cause and Effect, but that episode doesn’t qualify because every loop iteration actually happened.

Projections is a perfectly good early Doctor episode. It walks so that later Doctor episodes can run and be even more amazing. For me, in re-watches particularly, it has at least one too many fake-out to make it really great (the false ending with Kes in sickbay). A few more on that list a really good too; it almost pained me to put Living Witness on there for example because I love it. I felt a little better about it when I went back and saw that almost all the TNG episodes that do fake-outs were good to great.

Voyager constantly uses the "everything goes back to the way it was" ending, but I didn't count all of them because they're mostly not designed to fool the viewers. Threshold is a fine example of that trope and a bad episode (though I softened to it a little bit listening to the Delta Flyers podcast; at least I get what they were going for now) so I'm right there with you on that one.

Ha. Yeah, I enjoy a Doctor Who sometimes but I almost never actually retain them in my memory, and one reason might be because I know going in that they're all going to end in some kind of hyper-contrived insanity. Which isn't to say I don't like them, just that it's harder to remember stuff that has no connection to anything!

Yeah, now that people mention it I do think the VISOR would help quite a bit. Early on in TNG he even says he can detect if humans are lying from the minute physical changes (although the writers clearly drop that later, see his record at poker). Clearly that should be able to pick up all sorts of problems like internal temperature fluctuations and heart rate and in fact it does [The Enemy, TNG]. But what we don't see is Geordi ever fixing those things on a humanoid on screen. So he might be better than O'Brien, but I still think B'Elanna has the edge overall. Even if my logic is iffy (and it is: she fixes the Doctor so she knows about doctoring? Eh) on screen other characters acknowledge her medical skills. Including the Doctor, who gives her genetic re-sequencing idea serious consideration before she reprograms him. Would she be a better medic than even Tom Paris, who has a lot of practice but clearly doesn't like the work? I doubt it, but I'd probably take her in a life or death situation over the other engineers based solely on the primary sources.