Conditions for the validity of Salaah

Q: If I place a pure prayer mat on an impure carpet and pray on it but while making sujood the edges of my long jilbab touch the carpet, will my salah be valid?

Q: Is it compulsory for a woman to cover her feet during Salaah?

Q: If Maghrib ends at civil twilight end (depending on the place, 30-40 minutes https://www.timeanddate.com/astronomy/usa/chicago ), then why do apps prescribe a completely farther time for Isha?

Q: A person commenced his sunnat of Zuhar. Then he realized that the time of Zuhar is about to end so he changed his intention to fardh. Will this intention be valid?

Q: Can and imaam put on a short sleeve jubba to perform salaat in jama'ah?

Q: Can I combine my prayers? I have a urine condition where if I go to the toilet, then after a few minutes, I feel that there is a drop of urine coming out.

Due to this condition, I try to not go to the toilet in the daytime so that I can perform my prayers, but it is a painful process to suppress your need to relieve yourself.

Can I combine my Zohr and Asr prayers and then perform the Esha prayer with Maghrib?

Q: Can we delay isha after midnight? If not, what is the last time to pray isha?

Q: I prayed salah from puberty with proper wudhu but without ghusl for 7 years because I was not aware of the masalah of ghusl. Should I reperform those salahs?

Q: Can a woman only where a scarf whilst performing salaah? The hair is exposed in front?

Q: Is my salah in nike clothes valid?