If you are concerned with minimizing monetary loss rather than preserving working copies of your media [1] you can treat that as an argument for choosing a media provider that allows you to pay a monthly fee. If (when) their service gets discontinued you switch to another one; the only problem you would face is migrating your favorites, bookmark, playlists and the like [2].
[1] Which makes sense when the specific things you want to access (watch, listen to, read, play, etc.) are not rare and can be found elsewhere.
[2] Incidentally, this is something you could offer as SaaS. Edit: See http://resp.in/, http://www.getunify.com/, the FOSS project https://github.com/mauimauer/portify, etc.
I don't think this is a good strategy, you are putting yourself at the mercy of content license negotiations that are done by a bunch of idiots with their heads up their asses that you have absolutely no control over. There is no guarantee that the music you "rent" from one service will be available for you to "rent" on another service.
Yes, but ideally, when it's your cloud. Just because all these major cloud players can just stop their service on their whim.