Yes: https://arstechnica.com/security/2026/10/the-internet-goes-on-high-alert-after-discovery-of-8-compromised-tls-certs/

Not really imo

There’s an unofficial Teams flatpak or just use web. I use Thundebird for Outlook. For some reason Outlook refuses to work on my Firefox, so I use Vivaldi for that too. OneDrive is fucked, but there is an Rclone integration if you can convince your workplace to give you the correct API permissions. I have unfortunately not.

I would actually recommend PEN15 to anyone willing to listen