By staying at Royal Pacific, you will get Unlimited Express Passes, so there is no real need to make TPs. However, I still like to make them just to get a general idea of where the busy areas will be at what time of day. Since you haven’t been there often, making the TPs will help give you a good flow for your trip and help you see what areas you might want to avoid at certain times. Once you do that, you can basically throw the TP out the window and do whatever you want. You have low CLs to begin with and then the wait time for EP lines is generally 1/3 the wait time of standby. You will be in great shape.
The wee one can do the rides in Suess Land in IOA, as well as the play area and Pteranadon Flyers in Jurassic Park. There are also shows that might be enjoyable. USF will have shows as well, plus some play areas back in the kids zone.
I only made a room request once for a Universal hotel and it wasn’t honored, so I stopped after that. Unlike Disney, where the hotels can be very spread out and very far away from bus stops, I don’t find Universal hotels to be so huge, and thus, I, personally, feel location is not as much of an issue. I might try to avoid overlooking pools in case it gets too loud, but that’s about it. At Royal Pacific, you can walk to the parks along a beautiful walking path or take the water taxi to the parks.
My only real advice for touring the parks is that if you are going to explore the Harry Potter areas, do those early in the morning and later at night. Try to avoid them at midday, as even with low crowds, they can get very, very congested. Being in the areas with fewer people makes them much more enjoyable.