I don't know how much spare time you'll have but some of the suggestions you've received are a long way from Nice and would not IMO be best photographed from there. This is particularly true in a part of the world where traffic congestion is the norm and in one of the busiest periods. Unless you're able to spend a few days away from Nice in western Provence, my suggestion is to stay closer, and I might argue much closer, to base.
You also need to know, if you don't already, that the entire coastline from Cannes to the Italian border is built up, and that access to the coastline is not ubiquitous, but there are access points where you can walk through to a coastal path. There are a lot more hazy days than there used to be, and if I got up one day and found the intense, saturated light that the Impressionists loved, I'd count myself fortunate and get moving fast. I'd consider the following, in the general context that the earlier in the day you get to the popular places the easier it'll be to park, get a cafe table, get photographs
* There's a railway line that runs from Nice east along the coast an which stops everywhere though the stations are usually a little way back from the coast itself. Its a good way of getting to Villefranche ( nice harbour, steeply stepped and arcaded streets) Beaulieu ( good walk along Cap Ferrat to St Jean and the Point de St-Hospice beyond) Cap d'Ail ( decent walk along the coast in either direction); Monte Carlo/Monaco; Menton (pleasant colourful town, nice harbour,good old town, some good Italianate churches and a great cemetary on top of the hill overlooking the harbour. You probably ought to see all of these if you haven't been to the area before.
* There are a number of villages not too far away that are probably best visited by car. They tend to be little old towns, quite well set up for tourism but atill have enough about them to make them interesting with the possibility of a bit of solitude once you get away from the main street/square. St Agnes and Gorbio, behind Menton; Roquebrune, behind Cap Martin; Peille/Peillon inlnad fron Monte Carlo. Sospel ansd Saorge , further north and less touristed. Tourettes sur Loup , west of Vence; Gourdon, NE of grasse; Biot , near Cagnes sur Mer. Auribeau, NW of Cannes; Cabris, west of Grasse. The villages of Eze( the hill village not the nondescript "sur Mer" on the coast and railway), and St Paul de Vence wouldn't make my list- not because they are unattractive but because they are overrun and over -adapted to tourism.
* The towns. These are IMO the most interesting/Scenic though I have to say that I haven't photographed much in any of them. Antibes; Vence; Nice around the area of the Old town/Flower Market and round the old harbour; Menton.
* Beaches; not generally sandy in this part of France. I always liked the Plage de la Garoupe, on Cap d'Antibes which was private, sandy, cleaned daily and had beach restaurants where you could get lunch. The view here is NE and you night see snow-covered Alps behind Nice.