Various masaail of Business and Dealings

Distributing items which were jointly purchased

Q: I am participating in a technical project at my university which will be funded by the project's team members equally. The money collected will be used to buy parts and equipment for the project. During the project's duration, the remaining money will be kept reserved for use in case a part breaks and needs replacement.

After the project is over, the parts used in the project and the money will be equally distributed to the team members.

The parts distributed will be used, and may be worn. On what basis can the parts be distributed to the team members? Should they be distributed based on their value when they were bought, or should we estimate their current market value?

Developing a social media app where people will post pictures

Q: I am a medical student who is also interested in web development, therefore I was thinking of developing a social media app similar to Facebook where people would be able to post photos. What I am concerned about is if people start to post immoral/obscene photos about which I am pretty sure they will on the website. Will I be sinning since I am providing a platform for such content??

Writing complaints or negative reviews on websites

Q: There is a website called hellopeter.com on which people review the service they received from various companies, list their complaints, grievances or even praise the service. Most of the postings are complaints against companies. The companies thereafter usually respond and try to resolve their issues. Sometimes the company or individual changed their ways, or got rid of a problem employee, but the negative reviews were not changed by the complainant. 

Another example is that of Google maps reviews, which often can have a negative impact on a business when customers complain.

Both these websites are public and the complaints visible to all.

Is it permissible to complain/write a negative review, using these methods, against companies or individuals, with the hope of resolving legitimate grievances, such as non delivery of a promised service and the like? Or would this amount to backbiting?