Wondering if any can help with ideas for a few days in Liguria/Tuscany area. After a work conference in Bolzano area, I’ll have 4-5 days to look around. I love food, walking streets, not so into museums with such little time. I have been to Florence, lake Como, lake Garda, Parma, bologna, Moderna previously so was thinking 2 days cinque Terra but then where? Is San Gimignano worth it? Or Sienna? Flying out of Milan I can train or hire a car. Any ideas would be greatly appreciated.

What time of year?

Personally, considering the bookends of Bolzano and Malpensa and only 4-5 days, I think you'd be better off considering the Piemonte area (which is lovely BTW). Train to Torino (4+ hours), rent/return the car there, and train to Malpensa (2 hours). Four days would be great for exploring several small towns. Great food, great wine, beautiful scenery.

IMO the CT and/or Tuscany isn't realistic in the time you have, and the combo of CT and Tuscany would involve more travel than sightseeing. The train journey from Bolzano to a CT town would take 6-7 hours with multiple connections. Then, CT to Malpensa would take 5+ hours with multiple connections. Or, alternatively, CT town to Siena by train would take 3-4 hours with connections, and Siena to Malpensa 5-6 hours with connections. Driving would save a few hours in either scenario, but you'd have a one-way rental surcharge and pay to park the car in CT, etc.

If you haven't driven in Italy before, you need to learn all about ZTLs and how to avoid getting a citation for driving into one. Just about every Italian town has a ZTL.

https://mominitaly.com/ztl-in-italy/

Depending on how much time you get to explore around Bolzano, I'd be tempted to extend your time in that area. Otherwise, how about Bergamo, Mantova or Stresa (catch Alibus to Malpensa airport)? I think Cinque Terre and San Gimignano are too far with a short time available.

From the OP's other thread, I found that this trip is in late October... which IMO is the perfect time to visit the Piemonte region.