Okay, there aren't any frequently asked questions yet... but maybe some questions you are intrested in
You're right, strictly it isn't cloud yet but this may change. It is already web-based and I thought cloud sounds bedder than web-based.
You don't share it, because you have to login so it's privat and not public. If it is legal to give other persons access to your music-collection depends on the laws in your country.
This question isn't easy to answer. The best would be to have a dedicated server. But it will be also possible to use a local PC or maybe a Fritz!Box. Relay necessary is only PHP and MySQL so you could also install it on normal webspace. But there you won't have the possibility to change the codec (external programs are necessary for this).
I think all common Browsers. See http://www.jplayer.org/ for more Information. God is also if the Browser shows sites correctly after W3C guidelines (There is a known issue with the Android browser see ).