You do not have to remove the freewheel to access the wheel bearings.
There is space between the hub balls, if not lubricated they will make a tapping sound.
The remover slots on the single freewheel rarely work, we used to resort to a hammer and punch on the end bearing plate, sometimes damageing the freewheel.
Try running a little oil in both sides where the axle goes into the hub and see if the hub feels smoother.
Keith