It’s kernel level anticheat, it can do whatever it wants. It’s on the same level as the operating system.
Realistically? Nobody’s gonna bundle Linux filesystem drivers in malware just in case. If someone is to exploit Vanguard for malware I’d expect a credentials stealer to take your Steam and Discord accounts. Ransomware would likely spread to the NAS but that can be mitigated with readonly permissions where appropriate, and backups/shadow copies.
That shouldn’t be a problem, both Gnome and KDE gave decent accessibility features as far as I’m aware. Or at the very least, it’s got zoom, and the cursor can easily be changed to something of your liking. I think KDE’s also got the macOS “shake cursor to make it extra large so you can spot it” available.
I’m more concerned about
That’s not a lot of time, and if you’d rather not spend it tinkering I would stick with Windows.
I would at least make it a dual boot setup, so you can switch between Windows and Linux as needed. Don’t have time to tinker? Just do it in Windows until you have time.