VS has 4K resolution support for both the editor & for games. It's just not listed under the resolution dropdown. Use the explorer tool.
Yes, VS has support for PSN & Xbox One, but I believe you need developer licenses from Sony for PSN - not sure about Microsoft. PS license is very expensive from my understanding. If you have the licenses, you can talk to SimonS about it. It's not included in the regular export options for the game engine.