Praise be to Allah.
All praises be to Allaah, Lord and Sustainer of the worlds, and may the peace and blessings of Allaah be upon our Prophet Muhammad (peace be upon him) and upon his family and companions.
As-salaamu alaikum wa-rahamat ullaahi wa-barakaatuh, I ask Allah ta'ala that this message finds you all in good health and that He brings you success in all that is good. Before answering your most recent question, the following point must be made clear: Performing the duties of a mufti, a judge, an imam, a khateeb, or a mu'adhin is considered a duty of shari'ah, associated with the Hereafter, which must be rooted in one's volunteering and seeking the reward from Allah. It is not a worldly employment for profit or attaining income, and thus one cannot apply the principle of identifying a remuneration or compensation for specifically defined duties as one would do in the case of a worldly employment contract. If one cannot find those who are willing to volunteer to fill these duties without compensation, then it is permissible to arrange a payment for he who will execute these tasks and free himself up for them, since his duties as an imam or judge or mufti or similar functions may occupy his time such that he may not find the opportunity to gain his income through other means. Note that this payment is appointed for him for the purpose of freeing him up for his duties vis-a-vis shari'ah, and it is NOT a "fee for hire", i.e. NOT a salary compensating for work done. Thus, the correct case is that he accepts money so that he can be free to make fataawa (for a mufti), NOT that he makes fataawa so that he can make money; likewise, he accepts money so that he can be free to be an imam, NOT that he works as an imam so as to make money, etc. Both the correct and invalid cases are a means to an end; what makes one correct and the other invalid is what comprises the means and what comprises the end. The accepting of money must be the means, i.e. an instrument, aiding a person to the end, which is to establish and conduct acts of worship and pleasing Allaah, and to free himself up for this. Acts of worship cannot be the means to the end of achieving an income. Now we come to your question regarding giving the imam a portion of the zakaat which he is gathering for the purpose of the charitable project. This suggestion is based on the fact that he is among those who administer the funds, a category mentioned in the aayah regarding eligible parties that may receive from the zakaat funds. This category must be identified by its definition according to shari'ah, and it is: those officials appointed by the khalifah of the Muslims and their Imam for collecting zakaat, keeping account of it, guarding it, and distributing it among those who deserve it. Among the prerequisites required of those who collect zakaat are: that they are Muslim; that they are respected and trusted and don't betray; that they are reliable, trustworthy, and impartial, not inclined to favor anyone; fair and not liable to deal unjustly; knowledgeable in the required Islamic fiqh, aware of what is to be taken and what is not; disciplined and able to perform the duties. It is permissible for to give such persons a compensation from the zakaat itself or a salary from bait ul-maal from other funds. However, the official cannot take anything from the zakaat other than what the imam gives him, nor is he allowed to accept any gifts from those from whom he is collecting zakaat, as has been indicated by authentic ahaadeeth. If there is no khalifah of the Muslims to appoint those who will collect the zakaat or the khalifah has not sent someone to collect it (in a particular, perhaps remote, location), it becomes an obligation upon those who have wealth to pay it themselves and distribute it to those who deserve it. Further, the venerable Sheikh Abdul-Aziz bin Baaz has given us a fatwah indicating that it is permissible when necessary for the president of the Islamic center, or whoever is responsible for the matters of the Muslims, in non-Muslim countries, to appoint someone to collect zakaat and to give them an appropriate portion of it as a compensation, as they would be considered as among those employed to administer it. Important observation: If the person collecting zakaat is already receiving a salary from bait ul-maal such as a judge (qaadi), mufti, imam, etc., then he does not receive anything (additional) from the zakaat because he already has an income taken from bait ul-maal. In addition, the duties of anyone in such a position includes general work for the good of the Muslims (see Al-Mughni ma'al-Sharh al-Kabeer, Vol 7, p. 319, and al-Majmoo' lil-Nawawi, Vol 6, p.188). If what he receives does not cover his needs then he would be classified as being among the poor (al-fuqaraa'), and thus would be entitled to be given enough to meet his needs. Note, again, that he should not take anything himself unilaterally, so as not to compromise his impartiality and sincerity. And Allah the Most Knowledgeable knows what is best most correct.