So this was a short trip with a lot of highlights packed into just a few days.
Highlights were the rocket launch (obviously), visit at KSC (with an astronaut!) and the Universal Studios (the Harry Potter World especially).
Good info for watching rocket launches: we stood at the western part of the north side of Port Canaveral. Highly recommend to stand there. Just make sure you have some kind of internet connection so you can get updates of the launch so you know when it will be.
As for Universal Studios, an Express Pass is a good idea. There were not supermuch people when I was there so I would have made both parks without it, but it did go quicker with it - and ensured my that I would make it.