Conditions For Leading Salaah

Assalamualaykum Mufti saab,

I would like to know the conditions for leading the salaah.
In our University’s musallah we have some brothers who regularly lead the salaah.
Though they appear to be knowledgeable in matters related to salaah, they do acts which appear to be against the sunnah.

1. They lead the salaah without wearing a cap.
2. They have their trousers below their ankles all the time. (regarding this point when I advised one of the brothers he told me that scholars have said it is permissible to have trousers below ankles as long as one is not doing it out of pride). Is this correct?

Both these acts can be observed each time they lead the salaah. If any one other than these two is made to lead salaah, the same thing has been observed as mentioned in the above two points.

3. In addition, some of the brothers who lead the salaah are also clean-shaven.

I used to lead the salaah, but some people had objections that I do not give them enough time to recite Surah Fatiha. Since then, I prefer not to lead the salaah in order to stay away from such contorversies.

Mufti Saab I really do not know how to deal with such acts of gross negligence. Although there is another musallah in the University, I do not pray there as not many brothers gather over there. Can you please advise me how to deal with this issue?

Hope I have been able to explain myself clearly.

Looking forward to your reply.

Wassalamu alayk