

I think most other spam filters can get pretty good at you mark mail as spam and train it.
No idea about push. IMAP does have the ability to keep a connection open and get notifications and some mobile clients support that. My guess is, if the provider offers an app they probably support pushing to it somehow.

Depends.
Sometimes I just can’t find the actual thing by legal means. Go try listening to Bruce Woolley’s version of “Video Killed The Radio Star” sometime. I can either try to hunt down a physical copy or I can just pirate it. See also: most video game soundtracks.
Usually though it’s more about convenience. If I can just stream something on Spotify, I’ll just do that.
If there’s a movie I kinda wanna see but I’m not sure if it’s going to be good I’ll pirate it