So now I Have a Chinese version of the phone and cannot switch the launcher. Also some Chinese characters and screens pop up. No idea on how to stop all of that. I tried deleting as much stuff possible from the apps but there's some stuff that can't be deleted. Any tips on what should I do?
Only way to remove the launcher is by installing Nova or any other launcher and then using adb to remove the stock launcher. Had this exact same issue with my Vivo Nex Dual. Most if not all china set doesn't allow launcher change.
Also there's no way to rebrand the phone at the moment so the best bet would be to get a refund. How much did you purchase it for ? If they didn't state that it's a china set then you should be able to get them to refund you or changed to a global set.
It's only $850 here for the global version. You get the snorkeling case and also an extended 6 months warranty (not international warranty though). If you wan't to know more, drop me a pm.