At several times in the movie, one can clearly see the church of Santa Maria della Salute, one of Venice's landmarks. However, it could not possibly have been there at the time of Veronica Franco -- it was built a century later.
The books shown in the movie are printed on paper that is too thin and too white for 16th century. Also, the typeface is too small. Until 1843 paper was made exclusively from rags and this resulted in paper having large fibers and rough surface. Printing ink smeared on the fibers and so printers had to use large typefaces (equivalent to modern 16-18 points at least). White color of paper required and still requires copious use of sulfuric acid that was not available before industrial revolution too. It was not until late 19th century then modern quality paper, such as the one shown in the movie, was developed.
On Veronica's first night as a courtesan, Marco notices her and gets up from where he's sitting to speak to her. Maffeo is supposed to be reciting a poem, but in the shot of Marco rising, Maffeo is sitting right next to him.
When Veronica and Bea leave the sewing room, Veronica leans down to pick up her book. It is in her right hand and Bea's right hand is in Veronica's left hand as they leave the room and runs down the staircase. When they enter the street, there is no book and Veronica is holding Bea's left hand with (Veronica's) right hand.