A test on present simple and future simple

Hello,

I would be grateful if you chekced my answers. They are in bold.
Present simple or future simple test

1.Let's eat dinner when John gets/ will get here.

2.She will let /lets us know later, when she's ready to leave

3.I will wait/ wait until you're finished - then we can go.

4.John will study/ studies until he knows all the answers. ( I think both tenses can be used here)

5.She thinks that it will rain/ rains next weekend.

6.What do you want to do after the class finishes/will finish?

7.I think that the Democrats will win / win the next election.

8.I will give up/ give up smoking! (Is present simple also possible here?)

9.I hope she will come in time.

10.I hope she comes in time.

Is it possible to use either present simple or future simple in 5, 6, 7, 9?

Thanks