My two teens and I are traveling mid June for 3 weeks to trace our family roots in Croatia. The plan is Zagreb, possibly going to Plitvice while there, then Pula(day trip to Venice) Zadar, Split, Hvar then ending in dubrovnik. Couple days in each place, but a whole week in dubrovnik with family. Is it better to rent auto in Zagreb to pula or bus? Should we go to Plitvice from Zagreb or from split? Sounds I plan out touring Zagreb? Can anyone set up an itinerary for me? Should I bother renting car at all or just rely on bus/boat? Any fun tips for my 14 yr old son would be appreciated!
For three people, doing this by car will make much more sense than using buses. The roads are excellent and you can drive at high speeds to reach destinations quickly.
I'd suggest renting your car the day you leave Zagreb and turning it in in Split. You won't need after that, as you can take ferries from Split to Hvar and from Hvar to Dubrovnik. And getting to Plitvice by car (where you should spend the night and get an early start visiting the park the next morning) is much better than relying on buses.
How do you intend to do a day trip to Venice? It's over 3 hours by ferry each way between Pula and Venice. Check the schedule at http://www.venezialines.com/schedules. Are you sure you want to do that? You won't have more than 6 hours to spend in Venice, and it's a very long day.
I don't feel qualified to create an itinerary for you, as I only visited about half the destinations you are planning to visit. But laying it out on the map, here's what seems the best order:
Zagreb - Pula - Plitvice, - Zadar - Split - Hvar - Dubrovnik
Hope that helps!
Although I love Venice, I wouldn't try to do it as a day-trip from Pula, either. I haven't been to Pula myself, but I can tell you that both Rovinj and Porec are very nice and should be considered for day-trips while you're in Pula. They are physically very different. There's reasonably frequent bus service from Pula to both of them. I also enjoyed a one-day bus tour of the Istrian interior. Had to visit several travel agencies to find out about it, and I think it only ran one day a week. Tourists were bused to the starting point from several of the coast cities; I'm assuming Pula was among them.
I remember seeing some people zip-lining while I was on that interior Istria bus trip. I believe it was in Pazin, but I'm not certain.
Public buses run fairly frequently from Zagreb to Plitvice. I have no experience making the trip from Split. Do whatever you can to have early-morning time at Plitvice. It's a magical sort of place, but considerably less so when the bus swarms arrive.
I've traveled in Croatia three times, relying on public buses, but a rental car would be a much better solution for the Plitvice/Istrian part of your trip, and certainly economical IF you are comfortable with a manual transmission. If not, check now to see what sort of cost you'll run into for an automatic.