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? 

Reason for mutahayyirah performing salaah as a precaution

Q: It is mentioned in a fatwa regarding a mutahayyara that if she is in doubt as to whether her haidh has ended or not, she will take ghusl for each salaah time and perform the salaah of the time. When the next salaah time comes, she will take ghusl and before performing the salaah of that time she will perform the last salaah again as a precaution" So what does it mean as a precaution perform the last salaah again. How is that being cautious?What are they being cautious of?