Laws of Azaan

Q:

1. The azan of such a person, who shaves or trims his beard less than a fist is Makrooh tahreemi, is that particular person committing a sin at the same time while giving the azan.
2. Does such a person receive the rewards mentioning in the ahadith for giving azan (same amount, less or not at all).

Q: Is it obligatory for a female to cover her head during the time of 'Azaan' when she is at home? If not then why muslim women act like this? 

Q: I went to a Masjid and seen that the Muazzin calls the azaan with only one finger in his ears. The other hand is down. Is this authentic?

Q: Is it okay for a clean shaven person to give the azaan?

Q: At work we have a Namaaz room or Jamaat Khana. The question I have is that do we need to give azaan for the different Namaaz. At  times we have only 2 people reading the salaat but do not know if there will be someone coming. For Dhur Namaaz we have a Jamaat of about 4 to 5 people.

Q: I always hear the Muazzin say takbeer twice at the end of Azaan, but I now read in the revised version of Taleem-ul-Haq that it needs to be said four times. Kindly clarify?