Conditions for the validity of Salaah

Q: Just want to find out which salaah's can be joined (read at the same time) when one is a traveller?​

Q: I read that Maghrib prayer time ends when the redness in the sky goes away. Also I read that it ends half an hour before Isha Azan. Which one is true? Half an hour before Isha azan I feel the sky becomes darker. Can I still pray Maghrib or should I mention as qadha namaz? As I'm a working woman and gets little late to reach home and can't pray in van.

Q: Can we perform salaah with clothes on which has animals like Puma shirts, etc.?

Q: If fajar azan is at 4:45 am then what's the maximum last time tahajjud can be offered?

Q: A lot of people tell me that you can delay isha prayer till midnight, is this true?

Q: If I have filth on my clothes less than the size of a dirham and water touches it and the diameter increases from one dirham, can I pray in those clothes?

Q: I wear a trousers belt, it's leather. I don't know what kind of animal skin was used to make this leather belt. I heard that if you wear leather made with pig skin and if you pray salah with it, it wouldn't be accepted, it's nearly impossible to tell if the leather is pig skin or not because where you buy it, it doesn't says. Would my salah be valid? 

Q: I came to know by one of the dawat-o-tabligh elders that we can make intention of many different namazes (e.g: if we are praying ishraq then we can make intention of tahiyaatul wudhu, tahiyyatul masjid, salaatul hajat, salaatul taubah, etc.)

1. Is it true?

2. How many total extra niyyats can we make for a two rakat nafil?

3. Can we do the same for zohar, maghrib and isha nafl prayers?

Q: On a trip out of town that necessitated qasar salaah, my sister checked the qibla direction using 2/3 apps. 2 gave a certain direction and the 3rd gave a different direction. We thus read our salaah according to the qibla direction from the two that were the same. However on the day we were leaving, I was on the balcony watching the sunrise and realised the sun was rising on the exact opposite direction of our qibla direction. In my understanding the qibla direction is north east and the sun rises in the east which meant our qibla was incorrect. Is this right? This doubt is lingering on my mind. Do I have to repeat my salaah? 

Q: A fowl came into the home and soiled the carpet with droppings. Should I wash the soiled area only, or do I have to wash the entire carpet? If salaah was performed on the clean portion of the carpet before the entire carpet was washed, will the salaah be valid?