If you don't mind carrying the cat in the carrier, it should not be a problem. You would not want your cat to roam freely and get lost. City streets and sounds might be upsetting for house bound pets. Be advised that dogs may be present and not all dogs are leashed even though they are supposed to be. In the winter, we came across an unleashed dog and its owner on the park lawns just above Water Place Park and Riverwalk and the owner was having a very difficult time trying to get the dog back on leash. I'm not sure if restaurants would allow you inside with a pet but for outdoor dining in the summer, they may be more accommodating. If not, you could always enjoy a nice picnic on a river bench with your cat at your side.

There was one last night and they only happen once a month. Not sure how you find the schedule. Get there early. Maybe Uber so you don't have to deal with parking

It's just a matter of you'd like to make of it. You can start or stop any where along the walk. Your walking speed will dictate how long it will take if you do the entire route but I'd say one direction maybe an hour+

Well, you're probably already on your way, but parking in Providence is reasonable--IF you are not using hotel valet. I would try for the Biltmore garage, which is quite close to the action. If you wish to dine in a downtown restaurant, make reservation ASAP. Traffic after the event is not a factor; the performances go on until midnight and people tend to just trickle away. If downtown is too jammed, try parking on the street on College Hill. The walk is pleasant. Lovely eatery up there too: The Red Stripe. Whatever you do, don't park overnight in the garage at 165 Washington Street. They are closed on Sundays and I had to pay to have someone drive in from Cranston to let me out.

We went to Providence mid January so I have no first hand information but there is helpful info on the Trip Advisor attractions for La Gondola. There are also a web sites for Waterfire and Water place Park. La Gondola address is 1 citizens plaza

The Courtyard is right in the heart of Down Town Providence. Stay away from the commercial mall restaurants, and go explore Providences unique restaurants scene. The Roof Top at G Pub is a great place to see some nice views of the city and showcases Providences passion for Food and Beverage. There is also street vendors at Water Fire so leave dessert for one of the local ice cream stands. Nicks on Broadway would be the BEST place to go for breakfast, but expect to wait in line on Sunday morning to get into it. Well worth the wait. For Parking: The mall doesn't have the gates down 24 hours a day. If you leave early enough the Gates will be open and you can drive right out... ( I was at the mall 10AM Sunday and literally drove right out) Enjoy water fire, it is SO much fun !!