It is not the length of the beard or the age of an individual which qualifies him as an Imam. This is often the criteria used in many of our mosques. Some people have even turned it into a family thing. The moment the Imam dies, the son or any other member of the family steps in. Even if your family built it, it still doesn’t guarantee any member of the family an automatic slot.
The Holy Prophet said one who learns the Qur'an the most should always lead the solat.
It was narrated that Abu Mas'ood al-Ansaari said, the Messenger of Allah (peace and blessing of Allah be upon him) said:
"The people should be led in prayer by the one, who has most knowledge of the Book of Allaah; if they are equal in knowledge of the Qur'an, then by the one who has most knowledge of the Sunnah."-(Imam Muslim,1530)
By 'the one who has most knowledge of the Qur'an it is not the one who can recite it most beautifully, but rather the one who has memorized more of the Book of Allah. By reciting the Qur'an often, the people learn it the more. But this does not necessarily mean you should be reciting long chapters every time just to show off as Allah disapproves of showing off (Riyah) in Islam.
May Allah lead us to the right path.