Urge to Break Wind in Salaah

Q: I was performing salaah and during my last sajdah I felt accumulated wind about to come out i.e. I had the urge to break wind, when I sat back from sajdah that feeling was gone. Now I don't know whether the accumulated wind came out without me noticing it, or that the accumulated wind just disappeared into my body. In such case is my wudhu nullified? Can the feeling of accumulated wind just disappear (without coming out) back into the body? Or must I regard it as having come out even if I did not feel something coming out? Should I repeat the prayer and the prayer I have prayed after it?

Mazi Falling on the Garment

Q: Before going to sleep, very small amount of mazi comes out. After waking up it is impossible to locate exactly which part of the garment has the impurity. What should be done in this case? Can salaah be offered without washing the garment since the mazi is not apparent?

Reciting Durood a Thousand Times

Q:

  1. I came accross a hadith that says one needs to read a specific durood a thousand times and he will not leave this world until he sees his abode in jannah (something to the effect). Is there any hadith that says any durood could be read including the durood "Sallallahu Alayhi Wasallam" and one will get the same benefit? 
  2. I read at least one friday (begining from the thursday night) 1000 times "Sallallahu Alayhi Wasallam". Now am I guranteed jannah because we do not doubt what our prophet Muhammad (Sallallahu Alayhi Wasallam) said?

Sheep and Beef Casings

Q: It has come to my attention that a Mufti from abroad has declared the sheep and beef casings (intestines) that we use in the manufacture of sausages and wors as Haraam due to the fact that Najis passes through the casing (intestine) when the animal is alive. Please comment.