Yeah, get a new monitor. whether you go for resolution, refresh rate (which i think you’ve said is your preference in the past), aspect ratio, curvature, or sheer size, get a new display and then check appropriate benchmarks for hardware running things at it’s resolution. Or get VR. Or both.
Try various fans; every case, person, ear, PC position, and room etc combination is different, and for all their rep and reliability I’ve never found a Noctua fan i couldn’t replace with a more suitable fan. Except this shitty 92mm one.
From what you’ve said, don’t bother overclocking. That’s not a longevity game, and the gains you get will be wiped out by subsequent generations long before you look at upgrading. Maybe try it as a hobby or if you’re really into it, but if you’re doing it to get the level of performance you’re aiming for then you’ve got the wrong hardware, aim to buy something that does what you want. If you do that effectively you’ll never even notice the difference if you do overclock. That’s what happened with me on the 5820k; it overclocks great, it just doesn’t make an appreciable difference to anything.
Both Intel and AMD are switching from current 14nm and 12nm to 10nm and 7nm nodes in the next year (according to them, whether that results in consumer products you can buy who knows), so nothing that applies now necessarily has any relevance 12 months from now. You’ll be looking at new chipsets, boards, CPUs and possibly ram; there’s that intel favourite tactic of supporting new types of RAM on their top end chipset while supporting current/previous generation on whatever sits below it in their lineup. All you can do for now really is look at price points, and they’re likely to change.
You could upgrade your monitor now and go 4K, then you’ll really start to feel the pressure to upgrade and the other decisions will get a lot easier to make