Here is my room design thus far.
Due to the fact that it has multiple doors in the room that are at a different angle, I had to manually adjust the C++ code of the Rotator a little. Because the current code set the doors at a specific angle based on the world. Instead of adding 60° to the default door angle. So I changed that specific line to this:
FRotator NewRotation = FRotator(Owner->GetActorRotation()+FRotator(0.0f, 60.0f, 0.0f));
And honestly, I am pretty proud of myself to figure this out all on my own. ^^