Hopefully Sia will be able to grow to its fullest potential. I think Sia can change the world by offering cheap storage.
Getting sia should be more accessible, the process now is too long. You have to convert your money to BTC first and then you can buy Sia. At the same you also need to download a client and wait for it sync.
I would hope so. I think all these decentralized storage options are great, offering competition and driving prices down.
You are correct, once it is simple for people to store data on Sia, it will explode. For the time being they are a small team, but they are currently hiring more developers, so they should be able to pick up the pace.