Taking the initiative to lead the Salah

I have heard it is not good to take initiative to lead prayers in a group, but that the others in the group should appoint you. But what about if you are going to pray with a friend who is not suitable to lead the prayer...

Salah behind an Imam who is sitting down

Q1)Is it permissible for the Imam to lead the  Salaah  congregation sitting(due to sickness),the Imam does Ruku in sitting position and does Sajdah on the ground? Q2)Is it permissible for the Imam to lead the traveeh Sal...

Salah after smoking Marijuana

Salam, I just wanted to know if after smoking marijuana does your Salah still be accepted. If not, for how long? I am not talking about smoking then straight doing Salah, but like the next day or a few days after. Thank ...