Everyone seem to answer most of your questions just fine, so I can't really add all that much, but for wanting to be in the parks longer than 4 days, my advice would be to get you a 'after 6' pass on the 5th day. I honestly think unless the parks are wall-to-wall jammed, 4 days IS enough IMO. But, if you really feel like you need to do more, but don't want to pay for more full price tickets, that one comes in handy and you can pick a park of your favorites and do your favorite attractions again. The pass is around $25 when adjusted, so not a bad deal even though its only 4 hours in the park.
Or you can just buy another all day pass lol. Just a tip if you don't know about this already .