I probably should have mentioned that I don’t have a camrea, so I cannot give you any info on how that would work. My microphone works, I have shared my desktop (on KDE Plasma), and I have shared individual tabs. I can’t imagine that the camera would require anything extra to work though.

I’m using pipewire with wireplumber and didn’t have to install anything specific to have this all work, so I don’t have any info on if there would be any pulseaudio-specific issues.

I use Ungoogled Chromium for teams meetings at work without issue (on arch). I also don’t have an MS account.
When the other party sets up a meeting they’ll send an email with a link to the teams meeting and all you have to do is follow that link to join. It also includes a phone number you can call to join by phone if for some reason you have issues.

I found the same IPs doing the same thing for my server, but one thing I noticed in the access log was that nginx was returning a 499 status code. That code means that the client closed the connection before the server answered the request. So this seems to be a deliberate attack instead of the rash of bots many have been dealing with recently. They just firehose out requests to DoS the server since pagination on services with dynamic data is expensive.

I ended up creating a fail2ban rule to add any IP to my firewall blocklist that makes a bunch of 499 entries.

Edit: I also set a rate limit in nginx for any url that has a “page” query included