Firstly, all Ethereum blockchain transactions are not free-of-charge. Without commission project will lose money and be unprofitable. In addition, its a must to pay for marketing, office expenses and other. Sure, it is possible to create a project which will change the world, but its impossible to without proper work conditions. Thus, every project should be profitable and take money for any kind of service.
It becomes profitable due to token capitalisation! The more popular the project is, the more expensive its token becomes! Simple
Sure, it is possible. But in this particular case company must hold a huge part of total amount of tokens. And, of course, the company will be able to manipulate the rate of the token, for example - create an artificial collapse and buy out all tokens later. We dont want to blame anyone, this is just an obvious logic