Jamaat Salaah and Imaamat

Q: One day I was leading three people in zuhr prayer. In my second last rakaat I felt like something was coming out from my private part. I still continued with the prayer. After I finished I went to the toilet and I found it was mazi. I came back after I washed myself and made wudhu but the people we prayed together with were gone. I don't know where to find them because it was a market where we prayed. I don't know them at all. I then observed the prayer alone again. So what should I do about them?

Q: In the Holy Mosques of Makkah and Madinah, outside the mosques, there are big verandas (open space). It is seen that the people walk in these verandas with their footwear on.

1. Can we pray on the floor without a prayer mat?

2. Will our salah be valid? 

Q: Nowadays, some people are performing salaah in the hotel near the Musjid al Haraam while following the jamaat of Musjid al Haraam. The hotel has speakers installed and the recitation of the Imaam of Musjid al Haraam can easily be heard. However, since the Imaam is not present infront of the muqtadis, I am doubting whether the salaah is valid or not. Is it permissible for people to follow the Imaam in salaah while in their hotel rooms? Similarly, is it permissible to follow the Imaam in the hotel jamaat khaana? 

Q: Can the Imaam make a juma khutbah and perform the salaah with his scarf covering his face so much so that only his nose is exposed. When he goes into ruku the scarf hangs down both sides onto the ground.