Conditions for the validity of Salaah

Pants below the ankles

Q:

1) If you pull up your pants to ensure that it remains above your ankles before going down for rukhu or sajda, does it break your salaat?

2) If your pants falls below your ankles while reading salaat, does it break your salaat?

3) If you perform salaat with your pants below the ankles, is your salaat valid?

4) what type of movements nullify salaat?

Joining two Salaahs in one time

Q: Please advise on the ruling regarding joining of Salaahs when one is a musaafir. Most people join their salaah saying it is permitted as a musafir and better to join than miss it. And in which circumstances will it be permissible to join? If a person joins their Salaah regularly as a musafir will the salaah be valid?

When does Tahajjud time end?

Q: I have two questions which I kindly request you to answer me.

1. I have doubt regarding tahajjud Salaah. I want to know when it exactly ends. Say the fajr Salaah starts at 5.23 am in where I live , now. Till wheat time then can we pray tahajjud Salaah? I want to know the timing so I can rectify if I make any mistakes.

2. Can we recite salawatun naariya with a particular niyat to be fulfilled? Where I live people recite it 4444 times with a particular niyat he or she has. Is it permissible?