Lovely Idiom: 該不會？

(你)该不会...？is an idiom of question and negation. Chinese use it often. How to use it?
Kindly note the situation below:
If people think that you (or someone) seem inclining or intend to do something…, but your purpose is ambiguous and the action is not usual, then people couldn't make sure the intention behinded and just doubt it, so they might make a negative and questioned assumption with a kidding way to test your actual intention .

For example:
1. You called me for several times, (你)該不會是在想我吧? (missing me)
2. You visit that store so often, (你)該不會是愛上那個老闆吧? (fall in love with that boss？)
3. They speak so loudly, (他們)該不會是在吵架吧? (fighting)
4. The sky is so dark and grey, (天空)該不會要下雨了吧? (going to rain)
5. You came back so late, (你)該不會是去約會了吧? (date with someone)
6. Who ate my cake…(那個人)該不會是你吧? (Is that you?)
7. He didn’t reply me, (他)該不會在生氣吧? (angry)
8. You guys haven’t met for a long time, (你們)該不會分手了吧? (broken up)
9. You won’t go there alone, (你)該不會要我陪你去吧? (accompany with you )
10. How could it be possible that he bought a plane, (他)該不會中樂透(won Lottery)了吧?