How to implement character customisation screen similar to Black Desert Online


I have started using and learning Unreal Engine so I guess I am a noob still, however I have made some progress. I am just bumping my head against a wall at the moment regarding UMG / gamepad integration and mixing with real time Pawn.

As I mentioned in the title, I want to have a character customisation screen for armour /equipment and cosmetics that actually displays the character pawn and can be controlled (the interface and camera)with the gamepad. So the character pawn becomes non controllable when in that custom screen. ( I am thinking this has to be an instance of the Character BP since you need to be able to pause the game any time and the customisation screen would show the character in different Idle motion). The camera is to be controlled via the sticks and the interface is via the buttons and D pad.
The game has to enter a paused state when reaching the main menu Widget and resume with any changes when back to game ( I am thinking of transferring the changes to variables from the character BP instance to the controlled character in game upon exiting the custom screen) .
The customisation screen has to also display an empty background.

1* So I have tried creating a level just for the customisation screen and using Open Level to access but this obviously resets game when I am back and I just want to resume where it was not reload it.
2* I tried Stream levels and set the custom screen level as a subLevel to the persistent one but when I use stream Level / visible it switches properly to custom screen level and back to my main level and thereafter I cannot switch anymore (seems both levels are streaming but there is no way to hide/unhide?)
3* I tried building a dummy custom room under the main level with its own Camera and teleporting the Actor to the room. While this works, somehow I have issues coupling to the camera actor in that room (the code is in mycharacter Blueprint and I cannot easily access the custom level Camera actor to set as the object for Target with blend). If I try to set up the code in the level blueperint (which allows easy reference of level actors object ) the character teleports fine and the camera changes properly but I cannot display my customisation widget on viewport.

I am not sure if I am thinking about it in the right way? Also support for gamepad in the UMG widget is very poor compared to the implementation of mouse. I have been through different tutorials including the UE4 livestream and only very rigid vertically aligned buttons interfaces are shown. Nothing like BDO where there could be multiple hotspots left and right.