iPhone X, re: 3G shutdown!

Yes the phone will still work. your phone supports most of the primary lte bands. The only one really missing is band 71 (l600 for T-Mobile). This is usually only used in rural areas or to help penetrate building in cities.

The iPhone X an LTE capable phone, so as long as your cellular provider has LTE service in your area, yes.

FYI: 3G has already been shut down in most of the world.

They use band 12 and band 5 which is similar frequencies to 600. The x should work well for you.

yes, the iPhone X will work on 4G/LTE bands.

The iPhone X can function fine on 4G networks, you don't have to worry!

You're welcome.