There is nothing wrong with a man sleeping in the same room as his sister, each in his or her own bed, so long as nothing can be see of their `Awrahs.

There is nothing wrong with a Muslim listening to Quran before he sleeps, or listening to a lecture or anything permissible. Listening to Quran before going to sleep and after, during Ramadan and at other times, instills tranquility in the heart and helps one relax.

There is no sin on a person if he sleeps with his feet towards the Qiblah; rather the jurists said if a sick person cannot stand or sit, he should pray lying on his side with his face towards the Qiblah.

It is not permissible for you to sleep with no clothes on that would cover your `Awrah, whether you are sleeping with or without your wife. Rather it is permissible for you to uncover your `Awrah only at times of necessity.

Wudu before sleeping is a recommended Sunnah. If you are still is a state of Wudu from Isha or Tahajjud prayer, then you do not have to renew it.

Sleeping on your right side is the sunnah of sleeping. If a person does that to follow the example of the Prophet (peace and blessings of Allah be upon him), he will be rewarded for that. It is permissible to sleep on your left side, but you miss out on the reward for following the Sunnah.

The reason for the prohibition of sleeping on one’s belly is that it was forbidden by the Prophet who said to a man who was sleeping on his belly: “Do not lie like this, for this is how the people of Hell lie.”