Is it permissible to swear by (Allah "The Living")?
Yes, it is permissible because "The Living" is one of Allah`s Attributes.
Is buying shared land from someone who has taken possession of it considered halal or haram?
The shared land is possessed by the country i.e. for all people; therefore, it shouldn't be possessed/occupied save by it's guardian/owner permission,thusly it can't be possessed save by having owners' permission. Finally, buying it from a person who don't possess it is impermissible. And Allah Knows Best.
I work at a company that provides cash advances of 800 dinars, 1000 dinars, or 1200 dinars, depending on the employee’s years of service. An administrative fee of 40 dinars is deducted from the amount in the first month, and the remaining amount is repaid in installments. What is the ruling on this, knowing that the deducted amount (40 dinars) is fixed?
We fear that the deducted amount may be a means of circumventing interest (Riba). If the deducted amount is equal to or less than the actual administrative expenses, then there is no issue, as some scholars permit the borrower to bear the costs of documenting and managing the loan. However, piety suggests refraining from taking this loan under these conditions, as dealing with private individuals and companies is not the same as dealing with the state, which spends from the public treasury. And Allah Knows Best.
What is the ruling on not fulfilling a vow?
A vow is a commitment towards Allah, The Almighty, and so, it should be observed as much as possible, and it is impermissible to take it lightly. Allah, The Exalted, Says –in commending the believers (What means): "(Because) they perform the vow and fear a day whereof the evil is wide-spreading." [Al-Insan/7].