So questions, questions, questions. Let's start with the first one and move down:

1. I don't think any exist at the moment as the blockchain is fairly new to the world
2. It may, but I have some doubts, for example, the time it takes to load a picture from a single storing server unit even if it uncompressed is much less than loading fragments from dozens of randomly distributed storages with varying speed. Also how many people are familiar with blockchain and will the trust it? What if one device fails, will you keep same data on multiple devices?
3. YouTube , Twitter and Facebook ads. They'll probably do the job, maybe apply for Google ads but I don't believe it's much better.
   4.No, I don't think I know, try seeing if some freelance guys are into it.
   5.This is your decision, the latter is much more time and resources consuming but may work better, MAY. If it doesn't, it was a big waste.
   Well, those were my thoughts, take it as you like it but don't hold me responsible for anything as it is your decision after all.