sgtlion [any]

I would look at BIOS secyre boot/boot mode options. And depending on the age of the PC whether it supports UEFI or you need a legacy boot.

Yes. May need to turn off secure boot too.

Are they installed on separate drives? Depending on the exact setup, Linux and windows both generally support legacy as a boot method, so you may be able to just BIOS to select a boot drive.

I tend to have ~10,000 tabs because I obsessively fail to clean up. But it never takes much memory or cpu, my PC isn’t amazing yet Firefox is always lightning quick.

I’ve never used the discard or merge windows features though, I can see why those might cause issues. I assume these two functions just aren’t optimised for so many tabs.

One addon I might recommend to help keep numbers down is Duplicate Tab Closer, which has options to specify how similar tabs can be to be considered duplicates, and also will detect across all open windows if desired.

Honestly, IRC was a very functional, easy, free, low-resource and privacy friendly chat protocol and I don’t really see why it got left behind. If you wanted image/ file support that could really be implemented client and/or server side.

You can’t trust any of it to be totally secure, it’s effectively impossible. But, this is true of all software, at least open source is being audited and scrutinised all the time (as demonstrated).

All you can do is follow best practices.