"We detect an outdated Dokany version on your system" error even after deinstallation

in general: I would say “no”, and I guess the cryptomator developers agree. Thats why they made dokany the default virtual file system.
This might interest you:

Yes. Go To the settings of the cryptomator app (not the vaults configuration, the app configuration) by cliking the icon in the upper right corner. Select the 2nd tab from left and change the volume type.

Like you uninstall any other software on Windows. Go to System preferences → Apps and features. Select dokany and click “uninstall”

You search at the wrong place. Its a windows function, not a cryptomator function.

you only need to uninstall/reinstall latest version of dokany by hand. Or you can uninstall dokany and cryptomator, and then install cryptomator again, which will also install dokany in a suitable version.

Although Im using WebDAV too, I would not say this. It depends. If you want to handle files larger than 4GB or vaults that are larger than you system partition free space (no matter where you vault is actually located), then you don’t have a choice anymore and have to use Dokany, because WebDAV cannot handle this. In a most general aspect I would say dokany is the way to go, and default option.