re:  All engines have harmonic balancers ...

... and they're not somthing that's an aftermarket bolt-on
improvement.  Also, I think they are actually most of the time
separate from the pulley--they certainly are on the ubiquitous Chevy
V8.  Usually the balancer is cast iron and the pulley (with the belt
grooves) stamped steel.

re:  Any in line 2000cc four cylinder engine is going to vibrate ...

...except those with balancer shafts (not VW).  Boxer, i.e.
horizontally opposed fours like VANAGONS don't vibrate like inline
fours.

No big deal, just some minor points.