I'm not OP, but I do know a few things that can be done to make W7 safer and more usable. Security updates from Server 2008 R2 can be installed, those were still being released up until January 2026, so pretty recent still. Also, there are third party solutions such as 0patch, which will be issuing security patches until January 2028, but possibly longer if there is still demand.
As for browsers, there's 2 options (at least for vanilla win7), Firefox 115 ESR, which is supported by Mozilla until August 2026 (they've been extending this constantly though) and there's Supermium, which is a fork of chromium and works on XP
Also, for modern software compatibility, there is some exciting developments, mainly win32's secondsystem, which significantly improves compatibility with modern software. I know Adobe CC 2023 works with that, where the final versions to work ended at 2019/2020 depending on the software in question. Still early days yet, but we'll see how that goes.