Method of Salaah

Q: Does thinking of worldly things while in prayer makes the prayer invalid? How do I know that my prayers are being accepted?

Q: In salaah, after reciting Surah Faatiha, if a person is reading from the middle of a surah, is it preferable to read bismillah or not to read bismillah.

Q: If a Shaafi Imaam makes a major mistake in salaah which changes the meaning completely, what will happen to our salaah as Hanafis? And is there any difference whether we know about it or not?

Q: While reciting tashahhud, when one says Rasooluhu, instead of this if one says it as Rasooluh, does this constitutes as adding words to the Quraan if the person saying this knows that its Rasooloohu. In arabic is it changing A with O sound like 'zabar' and 'paish' difference?

Q: A person was praying Fajr Salaah, and during recitation of a surah, she felt that one verse of the surah being recited got skipped. So she repeated the surah again in the same rakaah.

1. Is the salaah valid?

2. Should the surah be recited again in the same rakaah if a person notices that an aayah got skipped?

Q: I have read somewhere that it is makrooh to pray near impurities. Is it makrooh if one prays in a room that has a toilet attached to it?

Q: I have read somewhere (I think it was Baheshti Zewar) that it is makrooh to pray in a place where one would get distracted. What is meant by being 'distracted' in this ruling?

Q: While performing salaah, if I stand for qiyaam and do ruku in a normal manner, but I sit on a chair and perform my sajdah and jalsah, is my salaah valid? This is not due to any physical ailment.

Q: If a woman is one month pregnant, can she perform salaah on a chair for the safety of the baby?

Q: If during the recitation of Durood-e-Ebrahim, someone mistakenly says "majit" instead of "majid", does it invalidate his prayer?