Conditions for the validity of Salaah

Q:

1. I prayed Fajr at about 6:02 and it expires on the calendar at about 6:06, but before I prayed I looked outside and at first I noticed it was light and at the distance I seen in the clouds a reddish smudge, like at the time of Maghrib. Can Fajr expire before the calendar time or is it 100% accurate?

2. I prayed Fajr Qada in-case and at my last rak'ah in tashahhud I didn't have khushoo as I needed to relieve myself, does this affect the validity of my prayer? I leant on one side to hold it and before tasleem I moved back.

Q: Is it impermissible to wear jeans during the namaz and also not to fold the jeans upto the heel?

Q: Asr jamaat in the Tableelighi jamaat Musjid is at 4:45 PM whereas in the Ahle Hadith Musjid it is 3:45 PM. So can I offer my asr Salaah at the Ahle Hadith Musjid?

Q: I want to know that is it permissible to offer Salaah wearing clothes on which deodorant or perfume is used?

Q: This morning I thought fajar happened around 6:35 so when I woke up around 6 I thought there was still time to pray. I went and made wudu and I am kind of sure that the sky was dark but there was like a very faint light when I started. I didn't think it was that late so I started praying. I struggle with OCD so it takes me a while to pray even four rakaat and when I was done the sky was still dark but it was a lighter blue colour. Did I pray at a forbidden time? Did my namaaz not count? I am so doubtful and my OCD makes everything so hard can you please tell me what I should do? If I have to repent or make it up do I read the prayer of repentance after making wudu?

Q: I have heard one is able to join prayer like zuhr and asr when need be. I am a student and I can never get any work done at home so I go to the library. Only the time between the two namazes are like three hours. Is it ok for me to join the two in this case because that gives me so much more time to sit there and get my work done?

Q: If I unintentionally make an intention of praying Asr fard Salaah instead of Zuhr and I realize that after the takbeer, then do I continue or break the Salaah?

Q: If you use clothing that has pictures with eyes and you cover it by wearing a jacket or jubbah, is your salaat valid?

Q: I read that using clothing with animate pictures are haram. Are we allowed to read salaah with a picture of an animal but it doesn't have the eyes drawn on it e.g. like a puma tracksuit pants?

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?