First Timer needs a little help

You should ask your friends how many years ago they went to the CT, and at what time of year. If you really want to go there, I would just spend two nights, giving yourselves one full day.

You know we have so many choices, sometimes you just have to pick one. But in this case, however, I am going to say pick choice #2. You already have CT which may test your patience during the day, so enjoy the regional feed and wine of Emilio Romagna. Do take some food tours.

You’re staying too long in the Cinque Terre. If you want to extend your time in Liguria, go to Santa Margherita Ligure or Camogli.
Yes, of course, Venice is “worth it.” But check a criuise ship calendar for your dates. Those huge ships disgorge thousands of passengers into Venice on day trips.
If your focus is food, then Bologna and surrounding towns( Parma, Modena) would be perfect.

Skip Venice and go to Bologna if culinary stuff is more important than the beautiful scenery and human traffic jams that you will experience in Venice during peak travel season. Same thing with Cinque Terre it is the best at night and early morning before when the day tripper is not there; 2 nights is enough as you may sick of the heat that swells with the crowds in July.

Yes, of course, Venice is “worth it.” But check a criuise ship calendar for your dates. Those huge ships disgorge thousands of passengers into Venice on day trips.

Are there any days when there are not multiple cruise ships in Venice? Not being snarky, it's a sincere question. I'm guessing that there are no cruise-ship-free days during the summer, maybe on the occasional lucky winter day...?

Venice is lovely and magical - at least it was when I was there. But for some of us, avoiding crowds has become one of (if not the single most) considerations when planning our trips. As much as I love Italy, there is no way you could get me to Venice or CT in July. There are other places, just as charming but not so heavily overrun with tourist crowds. You just need to put in some effort to find them. If you have your heart set on places like this, in the most busy season, just be mentally prepared for what awaits, and plan accordingly.

The total nights on the ground is 12 nights, from the 18th to the 29th.
Your last night (July 29) will necessarily be spent either in the city of Milan or closer to the Malpensa airport. Therefore you have a maximum of 11 nights to be spent elsewhere at your disposal.
IMAO (In My Arrogant Opinion), Venice is a must for a first timer visitor to Italy, and so is Florence, in spite of the fact that both are crowded, especially from April to October. Rome would be a must too, but your stay is too short and you appear to be flying in and out of Milan, therefore concentrating in Northern Italy only, skipping Rome, is appropriate.
How you allocate the 11 nights is somewhat of a personal choice.
I believe that on a trip of your length I would spend (either in this exact order or in the exact reverse order):
3 nights in Venice (spend also an afternoon in the islands of Murano and Burano)
5 nights at your villa in/near Florence/Tuscany (which gives you time for a couple of days devoted to Florence and a couple of trips elsewhere in Tuscany)
3 nights at Cinque Terre
1 night in Milan (before flying home)

You will almost certainly need a car while at your Tuscan location outside of Florence.
If you follow the itinerary above, I would pick up the car in Venice at Piazzale Roma (car rentals are located at the Municipal Parking structure on that Piazzale) and return the car at La Spezia, a port city next to Cinque Terre. If you do the reverse itinerary, you would reverse also the pick up and drop off locations (Pick up in La Spezia and return in Venice). The rest of the itinerary is best done using trains.

If you are travelling to Florence, and if you are on a trip for the local food of a region, and if you like beef, then a drive to Panzano in Chianti may be worth your while. Antica Macelleria Cecchini in Panzano is run by Dario Ceccini, a butcher/restauranteer who has made a name for himself cooking the best Florentine bifsteak around. He has been featured on the Netflix series "Chef's Table".
Give yourself about an hour to drive from Florence to Panzano in Chianti on SR222. Reservations are recommended. Check out the restaurant here: https://www.dariocecchini.com/en/
I also agree with other posters that CT is a two night stay. Too many people in the towns during the day at that time of year (cruise ship lines bus them in by the thousand), but the evenings can be wonderful. Looks like you're staying in Monterosso while in the CT; my wife and I enjoyed Ristorante Belvedere there, and also Ristorante Belforte in Vernazza.
Have fun!

Italian cooking, as with all things Italian, is highly regionalised. There are specialities in all regions, even Lazio and Rome, which are not easily available out side these small regions.

If you visit a variety of places and try the regional specialities I think you will be rewarded.

Regional cuisine is often based on what is available locally, so places with wheat fields will have pasta and places with rice fields will have Risotto. You won't get lagoon fish in Bologna, you won't get Risotto in Genova but you will get Pesto there, made with the local Basil.

There is a lot of tourist poor to awful food on the premise that they want it fast and don't care how it tastes and will never be back school of culinary science. But - there is also plenty of exceptional Veneto food in and around Venice if you are willing to search it out and pay appropriately.

There must be a reason that you chose to visit Italy in July - I always go earlier in the year south of the Alps - but you have what you have. In July there will be very few places in central and northern Italy not over-run by crowds, and Venice, the Cinque Terre area, Tuscany and Florence are no exceptions. You just have to find ways to deal with the crowds. Worse, for me, will be the heat. You can get away from the crowds - a villa in Tuscany sounds perfect for me - but you can't get away from the heat. For me in that regard Florence would be worst. Florence is in a bowl, like a furnace, and when the heat gets in it just builds.

Bologna, unlike some people, had less impression on me than many other places. Nice enough but not as special as some. Good regional food - I actually preferred the regional food just west in Mantova.

Good luck, DL, however it works out. And if you do get to Venice visit a few bàcari and enjoy the Cicchetti - you won't find that in many other places....

I would definitely say Venice is worth it, I was there during the busiest season and yes there are masses of tourists coming off cruise ships but they mainly hoarded around St. Marks square the the rialto bridge area, during the day we avoided those areas and did free walking tours (honestly far exceeded my expectations definitely worth it) in less busy areas and spend time exploring lesser known areas of the city (they were even more beautiful because of the local charm and feel)

One of the best meals I had in all of Italy was as La Bottiglia, they make amazing homemade sandwiches for lunch and had an extensive wine list. It was in a very very not crowded neighborhood.

I also HIGHLY recommend Nevodi, it was also in a quieter part of the city and had some incredible seafood dishes, we had dinner there 2 of the 4 nights we stayed. The food is so fresh too, more than once we saw an employee go across the street to a produce vendor and pick up some veggies for the dishes. Also directly across the street is a really cute bar where you can tell locals hang out (based on the crowd we saw and the price of an aperol spritz plus the free tiny bowl of chips that is customary at local spots)
If you take the water taxi to Burano or Murano you can see a quiet side of the city as well.

The absolute best part of staying in the city and not just coming in on a cruise ship is when all the passengers leave the city is all yours. The major sites were relatively quiet during the evening and really beautiful to walk around.

One way to escape the crowds at the Cinque Terre is to visit some other location during peak hour (10 to 4pm) or to hit the higher trails during that time. If you like being in the water, there are some spots along the trails that are nice. Since the trails are not at sea level you would need to climb down through some trails to descend to sea level. Those many spots are generally devoid of crowds. The cruise crowds tend to stay in the towns.

I suggest 3 nights on the coast, instead of only two, because it’s July and there is a reason why Italians hit the water in July and August. Temperatures in the interior are often unbearable. And don’t assume that Bologna is better than Florence because is more to the North. Bologna is one of the hottest cities in Italy in summer. Stay at your villa in Tuscany longer, preferably with a nice swimming pool.

Thank you all, so much for the opinions.
I've got more research to do, and switch some things around. I'll post again, when I return.
DL