I have been into Essen loads of times and not once been asked for anything other than my landing fee. You pay upstairs in the little ops room where you will the weather etc. In front of that is the tower which is actually a glass box on the ground. Very friendly bunch, cheap landing and a quick taxi ride into town. Can't comment on VFR as I only ever arrive of the airways but the service has always been good from the tower guys and ground staff.
Fuel is in front of the tower and can often involve a bit of a wait.
Flying in Germany is easy and worth doing. Other great places are Fridrichsaven (spelling?) Koblenz and Konstanz.