Is prayer mandatory on a dying person who goes through a state of unconsciousness, then wakes up?
If he wakes up and was conscious, then he should pray the way/manner he could, but if he wasn't, then he is exempted from obligatory prayer as Allah Says in this regard (What means): "On no soul doth God Place a burden greater than it can bear." [Al-Baqarah/286].
Is Zakah (obligatory charity) due on the items used in the trading process such as: cars , shops etc..?
No Zakah is due on equipments used in the trading process such as cars and the like.
Is it permissible for a woman to uncover her face while performing Umrah (minor Hajj)?
The woman while in a state of Ihram (ritual consecration) is obligated to uncover her face and hands, but at the same time permitted to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.
We collect funds from mosques and other sources, saying: "For the poor, the needy, widows, orphans, and those who do not beg insistently." After paying the stipends of the families registered with the Zakat Committee, an amount exceeding 6,000 dinars remained. Is it permissible for me to save it for upcoming months when I may not be able to collect the stipends?
These funds are received by the committee as representatives of the zakat payers to deliver zakat to those entitled to it. It is well-known that delaying zakat while being able to pay it is not permissible. Imam Al-Nawawi (may Allah have mercy on him) said: "Zakat must be paid immediately if one is able to do so, by the presence of wealth and the eligible categories." [Al-Minhaj] Therefore, the committee must distribute the zakat to the eligible recipients without installment payments or using it to purchase material goods for them, as the committee does not have authority over the poor to allocate it in this way. And Allah Knows Best.