Will Mac and Linux versions be exactly like the Windows version?
Eventually, yes.

Can I donate?
Yes, go to the donations page. BTW, a good beer here costs about $2 (usd) ;)

I'm getting a "404 Not Found" error in Ratio Faker, what can I do?
Chilax, if that appears just right after "checking for new versions" is because the server where is looking doesn't exist anymore. If it is somewhere else then is probably a non working tracker, eitherway there's nothing you can do to fix it.