You sound like a heavy printer if you are seeing that much on the wear and tear of the cabling. Are you running it 24x7?
I disabled my filament sensor as well for similar issues.
I’m surprised you are having issues with the hot end fan. Mine is stock, and I actually have to reduce the power when running PETG (245 C) because at 100%, the hot end can’t keep up. They really should have put a 40w or 50w heater cartridge in the hot end. I print in an enclosure with the original stock hot end, and I never have ran into any issue with cooling, though I am planning to go to the new r3 design but haven’t gotten around to it yet. It is a major pain taking that hot end apart.
Robox seems to be an interesting machine. One of the nice things about going with a Prusa or other main stream printer is that there is a lot of community support available. How is Robox in that regard? I saw they had a forum after doing a quick google, but it looks like a small/niche community.