What I usually do is tell the Play Store to not update it. Also, I don’t think it’s that involved. Take this with a grain of salt because I’m pretty experienced with phone modification, but I think it’s just downloading the file, opening it, selecting YouTube, choosing what modifications you want, and installing it.
Behavior-based antivirus is extremely difficult, failure-prone, and almost entirely unnecessary because of how secure Linux is, so they don’t exist to my knowledge. Signature-based antivirus is basically useless because any security holes exploited by a virus are patched upstream rather than waiting for an antivirus to block it. ClamAV focuses on Windows viruses, not Linux ones, so it can be a signature-based antivirus, but not many people run an email server accessed by Windows devices or other similar services that require ClamAV, so not many people use it, and nobody made any alternatives.
If you’re worried about security, focus on hardening and updates, not antiviruses.
This may not fit your needs, but matrix-docker-ansible-deploy is really good, and it uses Docker and Traefik by default.
At the very least, if Framework dies, many of the parts are standardized, and the ones that aren’t are mostly open source. The SSD, RAM, WiFi card, and screen connector are all standardized. The expansion cards use USB-C and have an open-source shape; many people have already made third-party expansion cards. The motherboard has an open-source layout, and there are open-source CAD files to make custom enclosures (again, people have already done it). There are general schematics with pinouts on their Github, and they’ve provided exact schematics to repair stores. If they die, you end up with a laptop that is more repairable than almost any other, as well as a community with enough information to keep it alive if they want to.
I have almost the same experience. I live in a small town in the Midwest, and the only ISP that goes to my house is Comcast/Xfinity. There’s a 1.2TB cap no matter what level you pay for, though they give you the option of paying an extra $30/month for unlimited. I’m really growing to appreciate our local ISP, which provides symmetrical FTTH, unlimited data, a static (or at least rarely changing) IP, and generally non-predatory business practices, all for a lower price than Xfinity. Unfortunately, my house is on the fringe of the town, so they don’t reach all the way here and I’m stuck with Xfinity.
.ovh domains are like $2/year, if that helps.