score:5
I've been in Venice last July, after the lockdown was lifted; it was business as usual, except for a reduced number of tourists (far fewer Americans and Chinese / oriental).
You can enter San Marco square, of course; the belltower has been open since the first days of June.
St. Mark's Basilica is still closed, but this isn't due to the Covid restrictions (it was damaged during the Acqua Alta last November). The Museum of the Basilica is open.
The various bridges (Sighs, Rialto) are open, and so are most restaurants and the traditional taverns.
Important: face masks are widespread; you'll have to wear them in all the public places, shops and restaurants. You can be refused service if you don't wear one.