What is the best way to organize decentralized data storage using your own resources?

Question

Data storage

Good afternoon! In the near future I plan to start developing a platform where users will share their personal data, which should not fall into the wrong hands, incl. and me, as the author of the platform. Blockchain technology (as a concept of data storage) suits my purposes, but it confuses me that I still depend on services such as: https://storj.io and http://sia.tech, which cannot guarantee data storage for a long period of time.
Based on this, I have a number of questions, I will be grateful for your answers:
1) What do you think that if you rent 60-80 servers that will be located in different parts of the world and will work on the principle of blockchain, acting as miners ?
2) How best to organize the storage of decentralized data so that only the author (user) has access, and if he sees fit, he could give access to others.
3) What is currently the most secure way of data encryption do you know?
Thanks in advance for the replies!

Answer 1

2) Encryption is quite enough - and on your servers. Work will be more stable than if you give to customers.
And on other people's computers - this is for the sake of saving their resources. But there is another problem - it will work stably only if your platform is highly popular.
3) Elliptic curves.
1) it's not clear what you mean.