Is it permissible to trim the eyebrows if they become excessively long?
Trimming eyebrows is permissible if they become excessively long, yet; it is reprehensible. And Allah Knows Best.
What should a worshiper who has forgotten a pillar of prayer do?
If he/she remembered the forgotten pillar before offering it in the following Rakah (unit of prayer), then he/she should offer it, and continue the prayer, then offer Sujood As-Sahw (Prostration of forgetfulness) at the end of it. But, if he/she remembered that forgotten pillar after having offered it in the following Rakah, then he/she should offer a new Rakah in its (the one in which he forgot a pillar) place, and offer Sujood As-Sahw.
I work in an accounting and auditing office, and among the clients of the office are restaurants, hotels, and supermarkets that sell alcohol. Our work is limited to collecting invoices, whether purchases, sales, or expenses, and recording them in daily books. We also review income and sales taxes on behalf of these clients.
You are more knowledgeable about the nature of your work. If you see it as assisting in wrongdoing, then it is forbidden, as Allah The Exalted Says (What means): "And cooperate in righteousness and piety, but do not cooperate in sin and aggression" [Al-Ma’idah/2]. However, if your work is merely documenting the reality, then I hope there is no sin upon you. The the pious predecessors (Salaf) used to take the tithe from the traders of the People of the Book, even if it included alcohol, after knowing the value of their goods. And Allah The Almighty Knows Best.
Do certain vaginal discharges and incontinence of urine nullify ablution, and should underwear be changed?
A person afflicted with constant impurity due to urinary incontinence and vaginal discharges is obliged to make ablution for every obligatory prayer when its time is due, and after removing Najaasah (impurity), and wearing a clean diaper. He/she is obliged to pray immediately even if the impurity is being released, and he/she is obliged to remake ablution, and the aforementioned for every obligatory prayer.