Is it permissible for the one who treats with the Qur'an to take a fee or accept a gift, and what are the conditions that must be met in this practitioner?

If a person treats people with the Qur'an, and is known for his piety, devoutness, and seeking reward from Allah, and is keen on benefiting his brethren, then if he is given a gift or a fee, there is no harm in that. This is supported by the hadith of the stung man, over whom the Companions recited Al-Fatiha and stipulated a fee. When he gave them a flock of sheep, the Prophet, peace and blessings be upon him, did not disapprove of them, but rather said: "Give me a share with you." (Sahih Al-Bukhari from Abu Sa'id Al-Khudri).