Italien lakes and Venice

It's that time of year and we are going to try Italy again, having had to abandon it last year due to floods and landslips. 

This year we have decided to travel down through Switzerland and visit the lakes starting with Maggiore. 

Hopefully then we will travel across to Venice stopping off at some of the other lakes on the way. 

We should be in Italy by the end of April. I'm well aware of the German holiday at Pfingst and have the dates for when it will be busy with Germans. My question is how busy will it be in the first 2 weeks of May. 

Also it's been a long time since we visited Venice and we had a car back then which we drove to a big car park and got a water taxi in. 

I'm looking for a nice site where it's fairly easy to get into Venice, we have a Motorhome and would prefer to leave it on site. 

Our intentions for this trip is to not spend long at each place, just a few days. It's more of a taster trip to see if we like it or not.

I'm not a lover of busy sites or noisy sites these days, so it might well be to much but if you don't try you will never know.

After Italy we are heading to Slovenia and Austria, back through Germany then back to Calais.

Would welcome some help with sites, places not to miss, no cities please. Things we should do.