The drop is real, not simulated. It is also very short. If you’re in row one you don’t drop far at all due to the way the track tilts the coaster down. There’s hardly any coaster to this “roller coaster” ride, which left me quite disappointed the first time I rode it. The cars do spin around a bit a few times. Not too quickly but something to be aware of if you have motion sickness.
As to the time question, yes, it will be enough time. Because it’s one of the busiest days of the year, you will not have enough time to do even half of all the attractions throughout the parks. If you want to ride Hagrids, you need to be there well before open and rope drop it. I suggest doing the FJ queue after that, then Hippogriff if interested, take the train, do Gringotts, and take the train back (diff each way). Do all that without stopping to look around. Wait times will continue to build throughout the day and even the train will see 60+ minute waits, especially from the Universal side. After you’ve taken the train back to Hogsmeade, then explore all you want. Buy awand now if you want but do the show at Diagon as it’s a shorter wait. Depending on what time it is when you’re done, do a few things in IOA or just walk over to Diagon. I say walk because at this point the line for the train will be huge. Explore Diagon, starting with Ollivanders if the line isn’t huge, and if there’s leftover time, see more of Universal.
Don’t forget about the shows. There’s two different Tales of Beedle the Bard. They alternate which one they perform.
If you find you have time, the Grinchmas show and the holiday parade are both excellent. Some people finish HP in four or five hours or less, some look at literally everything there is to look at, see all the shows, do all the rides, and eat in at least one restaurant. The latter will easily take six+ hours, especially on a busy day. I once spent an hour just walking around Diagon reading all the ads on the walls.
