I think you answered your own question there! A level designer does exactly what you described without the need to model. It depends on what you would like to do. Do you want to work in a big team on a big project? In this case, I would say that learning some scripting would be very complimentary and put you in a great position to be hired (a perquisite in most cases)
In any case, getting stuck into something like the Skyrim toolkit where you can use their assets would be a very wise move.
The most important thing is to just get started. Good luck!