Valid & Invalid transactions

Q: I want to make an app for disabled people. I want to make an app that uses text-to-speech and speech-to-text function. Text-to-speech has a robotic womens voice, so is it permissible for males to hear such a voice? Is it permissible for me to launch such app and sell.

Secondly, I want to make speech-to-text app for the deafs so that deaf can receive incoming calls, subtitles will appear, so is it permissible for me launch such an app? If any woman is calling, so her voice will be translated into text form. I think this background process will also be robotic. Is it permissible for me to launch such app?

Q: I purchased an unstitched ladies suit (shalwar qameez) from a shop 3 years ago. Recently when I gave it to tailor for stitching, she discovered that it had an extra pair of sleeves. What should I do with that extra pair of sleeves? Can I give some money for that extra piece of cloth to any poor person and use the cloth myself?

Q: I purchased an x-ray machine. Mr.X said that he wants to run the machine, and told that he will be giving monthly 20,000 rupees to me, and the rest of the profit will be his. Three months he gave me that amount i.e 20,000. The next two months Mr.X couldn't get enough profit, so he told me that he is going to give 15,000. I agreed as I don't want him to go in loss. Is my business in accordance to shariah?

Q: I need Shar'ee guidance regarding a certain trading transaction:

My relative asked me to buy a washing machine for him. The washing machine cost Rs.3000 for example.

1. Can I inform my relative that the machine cost Rs.5,000? He does not know that I will charge him extra. 

2. Can I first inform my relative that I started selling washing machines and then charge him Rs.5,000?

Q: I previously purchased a playstore account with 7 more girls in university. Now I am starting my own android app business so I will buy my own separate playstore account as my intention is to sell features of my urdu learning app. There is some different process to put the app on the playstore for sale. So I want to make a separate test app to test the process of selling.

My question is, can I do this testing on the previously purchased playstore account which is owned by the 7 girls from university and myself. I will only do the testing for the selling process with the permission of the 7 other girls. If yes, do I need to share my profit with those 7 girls when I will be selling my app later on?

Note: I will not put my selling app on this account which is owned by the 7 other girls. I will only test the selling process. 

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?