Could you please check these few sentences? Thank you very much, Writeacher.

1) The old man passed away (is "out" possible though the meaning is different) during the night.
2) The tests have to be handed in to the teacher before the end of the week.
3) I should do up the house.
I should do the house up. (both possible?)
4) It must be him who stole the ring from the ring.
He must have stolen....
5) I moved to my new house/into my new house/in my new house (are they all possible?)
6) An accident help up the traffic for more than an hour/for over an hour.
7) She handed in all her money to charity. (Is this sentence possible, better: She handed all her money over to charity).
8) Peter asked us if tomorrow we could pop in/drop in on him after school.
He asked us if we could call on him tomorrow after school.

1) The old man passed away (is "out" possible though the meaning is different) during the night.

Yes, both are fine, although the meanings are quite different!

2) OK

3) I should do up the house.
I should do the house up. (both possible?)
Both are OK, but the first one is better (smoother).

4) It must be him who stole the ring from the ring. There's a grammatical error in there. Do you see it?
He must have stolen.... OK

5) I moved to my new house/into my new house/in my new house (are they all possible?)
Yes, all are fine.

6) An accident help traffic up for more than an hour/for over an hour.
OK

7) She handed in all her money to charity. (Is this sentence possible, better: She handed all her money over to charity). Yes, the second one is better. I wouldn't use the first one unless I were handing in a test or something like that.

8) OK