2 - Hard to say for me, it depends if you’re happy with your current server and if it meets 1.8 series requirements.
3 - You can certainly do that, there will be some additional steps to enable XMR/XTR and some environment changes, going forward it is likely that there will be more of those steps in manual/custom installation.
4 - Again, docker is recommended and should make things easier going forward, but it is perfectly feasible to install 1.8 series on a webserver similar to earlier series.
The Players cache 2 days worth of schedule and content by default. Unless you think it’s going to take longer than 2 days to try and upgrade, and roll back to a backup of your original state if that fails, then it should be OK.
General rule though - if it ain’t broke, don’t fix it. If you don’t want or need any of the new features, stay put for now until you do perhaps?