How do you sell what you did as "it just worked"? Rightaway? You lied to them. You have your coworkers on an unmanaged machine with a foreign OS on the guest WiFi with custom networking. Don't oversell a workaround as a solution.
Simplifying the problem to "Windows" seems unfair, given how many problems you found. All of them still require a long-term solution for regular operation.
Do it anyway. Having anything behind a TLD that is tied to the political control of a tiny geographic area is insanely careless