1)

1. should

2. do you have to

3. wouldn't

4. mustn't

5. shouldn't

2)

1. mustn't -> must

2. have to -> do you have to

3. should to see -> should see

4. don't have to -> mustn't

5. don't should -> should

3)

1. would

2. most

3. don't have to

4. if

5. should