I think what's occurring here is a confusion about the difference between meals at BOG.
For a 7:30 ADR, it is Table Service. You will wait to be seated. Your server will then come to you, maybe not immediately, to take orders. The order will be sent to the kitchen. Even if you order dessert only, you will wait to have it plated and served. You will then eat, and your bill will come at the end of your meal (whatever you do eat). If you want to see Beast, you will queue.
This is not like B or L, where you order ahead, pay at a kiosk, seat yourself, still wait for food, but it is much more streamlined.
The parade is at 8:15/8:30 and 11:15. You will absolutely miss the early parade. The Spelltacular last year was at 8, 9:15, 10:40 and midnight. Some dates there is no 8 show. You might be able to see the 9:15 show, but you'll have to walk around the castle and try to find a spot; like most shows closer in is better. The 10:40 show is often awkward because it's after Hallowishes and the crowd movement is weird.
If you're okay staying until midnight, sure, use a 7:30ADR. If you're not, you're going to miss one of the best parades at Disney and probably have issues making the 9:15 Spectacular (because by then people are also starting to stake out ground for Hallowishes).