I did a Torino-Camogli-Milano trip almost three years ago. I had not previously spent any real time in Milano and had never been to Torino. Both are great!

Re your question about suggestions for Lake Como, my favorite villas/gardens are Villa del Balbianello and Villa Monastero. The last time I was on Lake Como, I was a bit disappointed in the gardens of Villa Carlotta. I'd also suggest a hike up to Castello di Vezio, the views of the lake are stunning.

The town of Varenna is just wonderful. I would recommend staying there rather than the more popular (for some) Bellagio. Varenna is also easy to get to as it is served by rail. I stay on the other side of the lake at Hotel Villa Marie in Tremezzo as I really like the owners plus the villa has a tower topped with a covered terrace. The views of the lake from there at night are just magic.

I second Dee Dee--Varenna is a superb place to stay. Very few of the other towns and villages there had as much I dunno, 'local charm'. Varenna felt more down-to-earth. We treated those other locales as daytrips and were satisfied with that approach.
*My students thereafter exchanged pen pal letters with the local kids in Varenna for a few years.
Best of luck with this trip OP EN.

I am done. The end.