Cancellation of a transaction upon a specific time limit

Q: I want to sell a piece of land. The total price is R1.5 million. The buyer will pay me a 33% deposit as an upfront payment and the rest within 6 months, and then only will I hand over the land papers and land to him. If the purchaser fails to give me 67% within these 6 months, the sale will be cancelled and the purchaser will lose the 33% deposit. Is this clause permissible (forfeiting the initial deposit)?

Selling sweets for a madrasah

Q: I am standing at a stall in a madrasah and selling things for the madrasah such as sweets, etc. The items do not belong to me but to the madrasah. Can I purchase items for myself from the stalls, or would this be impermissible since I would, in essence, be the buyer and the seller at the same time?

Working in a bank

Q: I want to ask that I am working in audit firm and currently I have to audit different clients. Currently I am in bank audit. Can I drink water from bank premises as mostly income of the bank is based on interest and whether I can eat t​he foods from the money which is given by bank to my firm and my firm gives us to utilize for foods and dinner etc as we have to work late night.

Selling ebooks on Amazon

Q: I want to write an ebook and to publish on Amazon Kindle. When somebody buy my book I get paid. Firstly the owners of Amazon are non Muslim so can I sell my book on Amazon Kindle. Secondly when a buyer buys my book I get paid. What if the buyer money is haram and mostly buyers are non-muslim and their money is involved with riba and other haram things. So this type of money will be halaal for me? When someone read my ebook ads are shown on their device sometime but I am paid royalties of my ebook not for ads so this is permissible?

Paying for an item upfront before the order is processed

Q: A person has a business where he sells day-old chicks. The customers order the chicks during the week and he delivers them on Thursday. However, the orders are not processed until they pay for the chicks upfront.

1. Is the deal correct since the customer has to pay when he orders the chicks and not when he receives them?

2. Sometimes, the chicks die before they can be delivered to the customer. Who will bear the loss for the dead chicks?