Etiquettes

Facing the feet towards the qiblah

Q: Is keeping the feet towards the qibla sinful? In hajj many people keep their feet towards the qibla and sit there or recite Quran like this.

If someone has to read salah lying on the bed, doesn't he have to keep his feet towards qibla?

At the place of weekly talim I always have to sit at tashahud position keeping my back towards the qibla as the seating arrangement is like this, so many of our feet is towards the qibla. Do I suggest to them to change the arrangements? 

Dua for yawning

Q: Someone mentioned that when one yawns then this is from Shaytaan and one should recite ta'awwuz.

1. Is this correct, and applicable all the time?

2. Should one recite أعوذ... Every time one yawns

3. Is there mention of this in the hadith, and what is the hadith.

4. Similarly with regards to yawning softly without making a noise, is this mentioned in hadith?