Pretty much any 19''+ crt will get 120+hz (a few screens can do 200hz+ https://www.youtube.com/watch?v=TdDKazOtjM8) on lower resolutions. CRTs do usuallly have better blacks, contrast, viewing angles and colors than any fast response/high refresh rate lcd. First person shooters are the only game with enough movement on screen to notice and really appreciate the higher hz (the steps visible when you do a quick turn are smaller, it feels more fluid). The input delay difference to good lcds is probably so small it's hard to notice vs a gaming monitor.
I don't think it's worth it for osu!. If you want to play with one and do find a good one, it'll outperform lcds in many areas.
A good crt is an all in one gaming/image editing screen.
Yes because 0 motion blur due to phosphor decay being much faster than lcd pixel transitions