I feel like I take a much more casual approach to music than a lot of the people who's posts I have read in this forum. I really love music and I can hear the difference between lossy and lossless music (most of the time), but I am not obsessed with only listening to the highest quality music. I prefer lossless/Hi-res but if I have to settle for lossy, so be it, I will still happily listen.
That being said, I subscribe to 2 streaming services, Pandora and Rhapsody. I use those services daily, for general listening and to discover new music. Prior to these services I was forced to buy music basically unheard. I would buy albums based on individual songs I had heard, or because I liked another of the artist's albums. Frankly, my success rate was abismal. I rarely purchased an album I really liked. As a result I didn't buy much music. While I may not be to picky about the SQ I am REALLY picky about what I like and I was tired of buying albums that I didn't like. Now when I hear a song or hear about an artist that interests me I look them up on Rhapsody and I can listen to an entire album or numerous albums. If I like something I put it into my library and continue listening to it. If I really like it, I buy it. I have purchased more music in the last 2 years, since I have been using the streaming services, than I did in the 10 years prior to that. Streaming music has totally changed my envolvement with music (MUCH for the better).
To answer your questions:
1) I don't think streaming music says anything new about society. My relationship with the artist doesn't change one bit whether I buy their music or just stream it. It feels like you may be overthinking it, to me it has always been very simple, the artists play it and the people that enjoy it, listen. How they choose to listen is irrelevant.
2) I think just the oppsite is true, streaming has provided me with a diversity of music that I would never have had access to previously (without spending 10's of thousands of dollars). Rhapsody has about 10 million tracks of all genres and ages. I can listen to anything from Classical to Pop, from Big Band to Hip-Hop and everything in between. Rhapsody has "New Release Tuesday" when they feature a lot of the music that was released during the prior week. I have been checking that out lately and have been listening to 1 or 2 tracks from most of the new albums. I am listening to stuff that I would never have had access to previously. There is also the likelyhood that it is easier and less expensive for new artist to have their music streamed that is is to have it published on CD's and distributed which should increase the variety of new music.
3) Economics. If other people find streaming as useful as I do then it should be very popular (everyone I kinow that has tried it, is still using it) and the music industry will try to make it work. If the music streaming business stays an open market system and there is a sufficently large number of consumers, the market will find an equilibrium. The subscription price will adjust to the point where a sufficently large number of artists are making enough money to enable them to continue producing music. It is a completely new business model and it will take some time to find the equilibrium point where everyone is happy.
Just my opinions.