you as you have seen can travel a number of ways and depending on ow much time you have got - can have the most scenic journeys imaginable.
I am now 70 years of age and due to health problems do not travel pulling a van through Europe.
my favourite route is as follows
from any channel port, head for the bypass around Brussels, to Leige and to the Moselle valley where there are numerous camp sites along the moselle. then go to the Rhine valley and head for Austria via. Stuttgart and Ulm. down through bavaria heading for Innsbruck and the motorway to the Brenner Pass (this section charges for a vignette but no Toll fee) up through the Brenner Pass into Italy and down to Lake Garda which if you are heading for Garda town has quite a few lakeside campsites. please try to avoid taking your van over onto the the other side of the lake as we did and found that the towns along that side are beautifull but to get to them by car means driving through a lot of tunnels, built with usual Italian expertise.
This in my opinion is the quickest way if you want to avoid toll payments.
the main roads in Holland, Belgium and France are magnificent although the autobahns in germany are at some points feeling the ravages of time. Italy (my favourite country) has every degree of road condition and the drivers to suit every occasion.
I could go on for ever giving my experiences to and fro from Italy. Go for it and do let it begin and end at Garda Ciao