I have automatic updates on everything. If it breaks, I fix it when I have time. If I don’t, it remains broken.

I could also just not do updates, but I like new features.

You might need to lower your expectations

Is it feasible to self host websites

yes

for small businesses

NOPE

Well, you say your business sites, so I assume you’re okay with downtime. I would absolutely not self-host sites for someone else’s business, because if something happens to the hosting (ISP outage, power outage, bad update, hardware failure, accidental deletion, misconfiguration, ISP block, flood/fire/storm, theft, I can go on) then it’s my ass on the line. Simple hosting is cheap, spend the few bucks for a lot more peace of mind.

Either this means you won’t get future updates, or future updates will still overwrite your change. The proper way to do this would be to mount your own config over the one in the container, though this may have negative effects if the container config changes in the future. You might be able to mount /dev/null over the log file if you don’t care about the logs at all.

I don’t believe there’s any way to specify modifications to someone else’s containers without making your own image, unfortunately.