I can help a little with the Switzerland part as I was just there in Sept. I kept track of my expenses. I was there for 16 nights.
Roundtrip nonstop airfare—Chicago to Zurich $885 (was on sale). $92 x 2 transportation to and from O’hare airport
Travel insurance $46 (this was just in case of quarantine as I have health insurance with my employer and cancellation insurance with my Chase credit card).
$300 for 6-self test covid tests to return to US.
$110 for an international phone plan with Verizon
4 nights in Basel $1348 (this was for 3 people as the room was shared with my sister and her husband).
5 night in Lauterbrunnen $976 (this was just for me).
7 nights in Lucerne $1755 (this was just me and at a more expensive hotel because my sister and her husband had hotel points to use. You can find cheaper. I have Hotel des Alpes booked for this June and that cost is $528 for 3 nights, 1 person.
Everything else (food, souvenirs, tickets not covered with the Pass) was $2200. I did spend a little more on food as I was helping my sister and her husband out. So, while we were trying to split those costs, I probably covered 50% of food costs instead of my 1/3 share.
Depending on your eating habits, your food estimates is probably too low. We easily spent near $100 on lunch for 3 people some days. I think our most expensive dinner was $150 for 3. None of us drink alcohol. That would be extra. But that being said, you can spend less on food. We often had sandwiches for lunch. We all like oatmeal so we brought some instant oatmeal from home and had that for breakfast maybe half the time. Two of our hotels had breakfast included, but we only took advantage of that a few times as we were often out and about before that started. And my sister and her husband like to eat, so I ate more on this trip than if I was just traveling on my own.
And while I think your food estimate might be low, your misc. expenses are maybe a little high. So, I think your total estimate sounds reasonable. And everything in Italy, especially the food, should be less expensive. I haven’t been to Italy yet, so I can’t say how much lower the cost would be.