1. Hamas disarms or says they did. I am sure Hamas will store weapons such that the IDF will not find them. I do not doubt the IDF will destroy all tunnels that they know of, but it would not surprise me if there are some undiscovered tunnels that won't be touched.
2. Once Hamas is disarmed, the IDF leaves. There's a post on that already.
3. Hamas will rearm itself, no question about it in my mind. One wonders if they can get their hands on nukes or dirty bombs; I do not doubt they will use them if they get them.
4. At some point, another Jewish massacre will occur. I have no doubt of that either. Maybe not until Trump is out of office though. I'm sure the IDF will have plenty of surveillance, but I ain't sure they can interdict arms coming back into Gaza.