All in all looks good, I can see the appeal of the aquarium and the Tower in Pisa, for the kids.
You might want to add the Spianata Castelletto to your list in Genoa - this is a beautiful observation point on the city, accessed either by foot (maybe not so suitable with young kids) or by funicular. It's a bit tricky to find the station at the lower end, but the view is worth it, especially if you have a clear day. There's a gelateria at the top, and I believe that there are evenings when pizza ovens are put out on the large balcony, you might be able to check with the locals.
Speaking of gelateria, no lack of them in the city, we really enjoyed Viganotti (
https://www.romeoviganotti.com/gelateria-artigianale-genova/), but you could eat at a different gelateria twice a day and still not cover them all...
I suppose that you've taken into account that the round-trip to the Tower (if you're going by bus or train), is something like six hours, and that it might be a good idea to reserve a time-slot ticket in advance, if you plan on going up the tower. Maybe this isn't relevant, but you might want to consider saving the Tower for another time (in order to spare being on the road for six hours of the day), and perhaps go for a shorter trip to one of the towns along the coast, or perhaps the Cinque Terre. These could also be accessed by the sea, which the kids might like.
Have a great visit there.