1. The server update rate influences both overall interpolation as well as registered shots (lesser chance a critical shot not being registered), hence influencing the overall duel experience, especially in higher levels. Again, you cant use the term placebo when something is unarguably measured. Your subjective feeling (you not noticing it) doesn't make it a placebo, because it simply isn't. If you think it is, I would refer you again to the definition of placebo.
2. Going by your line of thought, again please, load csgohub.com, shoot 500 bots on 128 ticks, than immediately on 64 ticks. Tell me its the same, and please, be honest, even if your ego will take a hit. Peace.