Yeah I've been hearing this for so many years. If it were to affect gaming on Windows, it will definitely not happen. MS would be crazy to kill the stronghold they have on gaming.
I actually built a PC for a mate with almost exact same hardware a couple of weeks ago.
Temps were perfect from get go and this time round I used stock thermal paste from the cooler.
Unmount and clean off thermal paste.
Reapply thermal paste.
Carefully place pump back on thumb tightening each screw in a star shape. Do a few turns per corner to ensure even pressure.
TBH, I didn't really know when to stop screwing as it didn't feel like it was getting tighter to an end point and I was also being aware of overtightening too.
From memory, I think I did maybe 12-16 turns of each screw?
Good luck!
I'd love it if one day we could talk and have conversations with NPCs rather than clicking on a choice of scripts.