our total trip will be 7 nights, is 2 for Venice and 5 for Nice a good split? what should we see for sure, so we won't be rushing all the time and have some time to relax as well. what is the best way to go from Venice to Nice?
Your best daytime train route is Venice-Milan-Nice. See the timetables at www.bahn.de. After you get summary timetables for Venezia Santa Lucia-Nice Ville, click on the arrow to the left of each route to see the connecting points.
Baboo is a budget airline that flies directly between Venice Marco Polo and Nice. See www.flybaboo.com.
We can't really give you a meaningful answer, to your allocation of days question, unless you tell us more about your personal travel preferences, what you are looking for in a destination: Venice and Nice are very different. So please reply and tell us if you're looking for beach time or what? Also please state the month of your visit, it makes a difference re the advice on how many days in Nice.