Valid & Invalid transactions

Q: I work at the airport at a car rental. Now if a customer comes and wants to pay in Euros but we accept only Dinars, to make his work easy I take the Euros from him at the current exchange rate at the airport knowing that the exchange rate will be better outside in the city. So I accept those Euros and use my Dinars to give to the company and later take those Euros and exchange it in the market at a better rate for myself or sometimes I wait for an even better rate. Is this money halaal? 

Q: Many people do business and import items from foreign countries. Due to our country charging tax on the items imported, many people get the item invoiced at a lower price in the foreign country so that less tax is paid. I would like to inquire regarding the permissibility and rulings regarding this.

Q: I bought a donut from Dunkin Donuts because I was hungry and it ended up being heart shaped because of Valentine’s Day. I do not celebrate Valentine days and did not know that it would be heart shaped. I was not sure if I should return the doughnut but did not want to waste food so I ate it. Did I commit kufr or a sin ?

Q: Some online retailers clearly mention that the item is not in stock, and they will acquire it for the customer from the supplier. In this case, what should one do?

Q: Online retailers often sell items that they don’t keep in stock. They conclude the sale and take payment immediately and thereafter acquire the item from the supplier and deliver it to you. Similarly, when hardware stores sell bricks to customers, they conclude the sale and accept payment immediately. Thereafter, they buy the bricks from the supplier and ask the supplier to deliver directly to the customer. Is it permissible to deal in this manner?

Q: Is the trading concept of ‘drop shipping’ permissible? In ‘drop shipping’, the trader does not keep stock of any item. Instead, he accepts payment for the goods and then forwards the customer’s details to the supplier who will deliver directly to the customer. ‘Drop shipping’ is commonly found in online shopping. Is this permissible?

Q: I know a person who imports goods from China. He is offering to sell one of his containers to me. The problem is, I don’t know what goods are in the container, and if I buy it, I will have to sign a clause that I won’t be able to return it to him. Is this sale valid in Shari’ah?

Q:

1. Can I design products with logos of other brands and sell them online? Is that income halal for me? Especially if those brands are based in countries which are causing harm to Muslims and Islam?

2. Do I have to tell the buyers of these products that they are replicas, even if they are from a country which is harming Muslims and Islam?

Q: My neighbour wanted to buy a cooking pot for R100. I told her not to buy it as I will get one for her for just R70. She agreed because she was saving R30 on the same pot. However, my intention was that I will buy the pot for just R55 and tell her that it cost R70. In this way, I will make R15 without telling her. Is this permissible?

Q: Please advise if the following type of transactions are valid, not valid or improper:

A business has an agreement with a supplier to pay after 30 days from date of delivery with a limit of R50 000.00. 

1. The business puts a condition on all purchase orders, that should the supplier request an earlier payment, it will incur a early settlement discount of x% on a daily basis.

2. At times the business goes over the limit of R50 000.00 , hence early payment now becomes binding in order for the supplier to deliver further orders, can the business in this situation claim the x% early settlement discounts.