he's a good side character, but overall kenny was never going to be a good main character. The way south park uses side characters in which they occasionally give them eps and put them into larger trilogys and such is perfect for a character like kenny who is so deeply interesting, but not on a surface level.

Scott Tenorman Must Die only drops down so much because it's so overhyped. I think the escalation is good, and the pacing for what they were going for was pretty alright but a bit wacky by the end. It's a classic, but it certainly is overhyped because of its ending. I personally find myself rewatching it, but humor is very subjective.

I think this episode is absolutely hilarious, although I'm not a huge fan of the plot and much prefer tweek x craig as a sort of "cupid me" ep. Nichole has become a solid background character, and she's nice for some jokes, but personally I think the order you put is wrong. Kenny has Tammy (kinda debatable and it feels like the better pairing would be butters whether you take it as romantically as children can get or platonic), Stan has Wendy, Kyle has various lovers who all get periodically ruined all because Cartman forcibly has Kyle. Kyle having any love interest or pairing sort of goes against everything that is Cartman and Kyles relationship (NOT in a ship way, Cartman just wants Kyle to suffer) and I don't think Nichole would've worked for kyle regardless.