Salaah

Q: Is it permissible in Islam to have a tattoo on one's body? I performed salaah behind a person who has a tattoo on his skin. Is the salaah valid?

Q: What's the status of the Salaah of the Imaam and the muqtadees if the Imaam is known to be a follower of a certain mazhab eg: Shafi, but when he goes on the musallah he performs namaaz like a Hanafi, when questioned why he does that his simple answer was "I don't want to confuse the people". What is the status of the muqtadis and Imaams Salaah?

Q: I have a question regarding Salaah. For eg. In Esha Salaah there are four rakaat's, in which two are audible and two are silent. What should we do in the last two rakaats? 

Q: I always hear the Muazzin say takbeer twice at the end of Azaan, but I now read in the revised version of Taleem-ul-Haq that it needs to be said four times. Kindly clarify?

Q: Are there any specific virtues for performing salaat-ud-duha and how do you calculate its time?

Q: Is it permissible to sit on the chair and perform salaah? If yes, what are the rules regarding sitting on the chair? If sitting on the chair and reading namaaz is permissible then is it permissible to sit on the chair and eat?

Q: Is it permissible to read Salaat-ut-Tasbeeh in Jamaat.

 Q: If a traveller leaves his home for the airport (approx. 25 km away). At the airport, will he have to read qasr salaah or full?

 Q: Is there qadha for taraaweeh salaah once the time passes?

Q: Can one perform qadha salaah for the deceased?