Bitcoin becomes valuable because of its usage. It helps the economy also to have a fast and vast transaction. So, why do we need to hate this new innovative currency, if it can be a substitute and will be used for a long term purpose?
No, It does not help any economy at all, I'm pretty sure Bitcoin is an asset. It can not be a substitute(for now) but rather an alternative, I'm pretty sure you're using Fiat right now and still will for about 10 more years, even more
Opinions vary on this one
For sure, Bitcoin is an asset, and a speculative one at that, for the most part. However, it is still a good value transfer vehicle, and still more so if you don't want to show your wealth to anyone, especially the prying eyes of the government and their greyhounds. It doesn't know borders, so you don't have to bother about ridiculous financial regulations (read, limitations) imposed on international money transfers (which could be a pain in the ass). This is where Bitcoin can be not just a substitute but often the only option available (say, for the unbanked)