We were just there Sun-Tues of this week with our DD whos 9 (2 nights but 1 full day and 2 half days at RP) and hadnt been there since the mid-90s too. Daughter is not a major thrill ride, so we skipped the big coasters. Between the one hour early entry for Harry Potter and the Express Pass, we were able to do everything we wanted with time to spare. Even enjoyed some pool time the middle of our full day.
When you get to RP, you can check-in and leave your bags (our room was ready before noon so we took our bags up first). You get your Express Pass right in the lobby of the hotel (can do will call or buy your tickets there too) and then walk on the path to the parks or take the shuttle boat over. Its just as quick to walk, although the boat ride is a nice alternative. It does take a little bit of getting used to the layout of the RP but just ask for help and keep an eye out for signs. Hotel is nice (but if it wasnt for the value add of Express Pass I would say its overpriced for what you get in a room) and overall quiet once we got into our room.
We were at IOA 15 minutes before early opening, went right to Ollivanders and Forbidden Journey. Checked out Seuss and Marvel in the AM and did water rides around lunch (bring spare clothes/shoes- youll be soaked). I suggest IA on Friday so you can take advantage of early entry, then when everyone else is pouring in you can enjoy walk on to everything else. We did US our first half day and were able to do all the rides we wanted (and some twice), however we didnt do any shows and skipped Rip Ride Rockit. BTW- the parks close early- 7pm this week. You can fit in some pool time or we had a great time having dinner at Citiwalk (use Open Table to book a reservation the same day-definitely different than Disney) and then played a cool game of putt putt golf.
Have a great time!