Hi, i was not there for some time and now i will start with the pingplotter - you are pinging server and infrastructure generally which is not responding to icmp requests (ping) and is set to drop all ping requests after first few responses. But looking at the other hops, they dont seem to be the issue.
What i may consider as a bit alarming is your router, it has some ralink chipset and this brand chipsets are not usually the best and are known for weird behavior and issues... Not all of them but its an usual suspect.
Unfortunatelly i dont see any video, yes, crt is flickering, thats normal, just give us some youtube link (record it as slowmo and we will speed it up back to 240fps by replaying it at x4 speed).
For blurriness you need to know how to use a camera generally, you need to manually focus + manually set ISO and shutter speed to fit it to the recorded screen (and white ballance if automatic is bad but this wouldnt cause blurrines, only yellowiness). Also some cameras have minimum focus lenght too long, you need to keep camera above the minimum distance (and zoom in if its too far away).
Your issue with sharpness and blur is fully solvable, also disable optical stabilisation so it doesnt try to stabilize your movement in game (causing permanent zoom-ins and zoom-outs), even if i forgot to do this, i managed few weeks ago to get relatively usable recording at my low end mobile phone (look here at this example:
https://www.youtube.com/watch?v=So-iiTrGiVs - maybe not the best but definitely usable, i was recording to find out why i undershoot permanently - then i realized that im sitting too low so the crosshair seems to be higher than it is in POV, blatant issue solved easy by recording off screen
) so its definitely possible. the flickering of CRT doesnt matter so much, at frame to frame analysis the flickering is visible only at some frames, not at all of them. Now im gonna to do the same with my 240fps dji action 4 which is a bit more tricky due to much wider FOV and relatively long minimum focus distance (great for recording keystrokes and mouse clicks, not so great to analyze what happens at monitor). EDIT: DJI action 4 definitely doable, the most tricky thing is to control its too wide FOV, narrowest mode FHD can make it (this is only 60fps test to test sharpness and visibility)
https://www.youtube.com/watch?v=9BDGKXtbKzs Another choice is to set camera far far away with 15x macro LENS which will allow 4K recording but for a terrible price