Hi Andy,
Welcome to the forum. You will find loads of info on here.
Afraid I cannot help you with new Port Richey.
Yes, you do need careful planning at the parks. They can bee very tiring, especially with youngsters. Many visitors pop back to their villa in early afternoon for a cool off and bite to eat then back to the park. Your family will choose which parks to visit so when you first enter the park you will receive a map and timetable of events. Spend a few minutes studying the map and plan your day.
The airline carrier will give each of you a green visa waiver card to fill in (get 2 or 3 spare ones)which yo then hand to the immigration officer when you land. You will also be given a customs declaration form to hand in at customs. One of these forms is sufficient for all family members.

Have a great vacation.