The only easy job on your hand is changing the reading lamps.
The problem with the door lock definitely requires removing the door panel, as well as for changing the stupid light bulb for the seat outline switch. This is something that has to be done very carefully, since your car car has heavy door panels with lots of wires attached to them.
My old '81 300TD had the same problem on a rear door and it turned out to be the mechanism that moves the lock up an down (it leaked). No problems on the lines itself.