Valid & Invalid transactions

Q: I am working as a pharmacist in a big hospital. Our market is a generic market where the doctor prescribes the chemical name on the prescription rather than the brand name. The brand is selected by the pharmacist. The same medicine will be sold by different pharmaceutical companies under different brand names but will have the same chemical name. Example, the chemical paracetamol is in brand names like adol, calpol, panadol, tylenol, etc.

My question is that representatives from the pharmaceutical companies come to us and tell us that if we sell their company brand, they will give us some vouchers or a gift. Is taking this gift or voucher from the reps of the pharmaceutical companies allowed in Islam?

Q: A supplier sold fabric to a customer and delivered it to him. The fabric has not been paid for by the customer and it is highly unlikely that the customer is in a position to pay due to his severe financial debts. Do the goods belong to the supplier or customer?

Q: I want to open a business with boating, roller coaster rides, and other similar facilities. Can I provide such entertainment to people for a fee?

Q: I am in the business of buying and selling car mags. A few months back, I sold a set of rims to someone for R1800. A couple of months later, I got a call from the same person asking if I want to buy these same rims back because he had no use for them. I made him an offer of R1200 and purchased them back. Is this considered as riba or is it permissible?

Q: I would like to know the ruling regarding a person who contacts the seller of a property knowing well that someone else is busy negotiating to buy the property. Is it permissible for the second person to approach the seller to offer him more to secure the deal?

Q: When we make purchases online, some companies deliver their goods on cash on delivery terms. But they or a third party (delivering company) charge extra if one pays cash on delivery but no extra charges if we buy using credit card. Is it permissibe to pay the extra charges ?

Q: I live in India. I own a shop. I have to sell it. Can I sell it to a bank or can I give the shop on rent to that bank. Will it he halal for me?

Q: I want to ask if futures trading is halal in Commodity Market. In my country Pakistan, this is allowed. Also, to make it clear this kind of trading has no interest (riba) associated to it. Its a contract to buy the commodity in future by depositing an initial deposit. Please advice. I am a sunni Hanfi.

Q: Is it permissible for a seller to fight with a person for an amount of 1 lac because the purchaser does not want to pay the remaining amount of a property purchased due to some reason. Is this amount halaal for the seller or not?

Q: Please advise on below:

1. Many companies state at the bottom of their invoice "goods remain the property of the above company until fully paid for" What is the status of the goods?

2. Is it amaanat or does ownership pass on to the purchaser? Is such a condition permissible?

3. Will the sale be faasid if such a condition is added?