When Foobar is minimised and in background, if I hear a song I dont like how do I remove it from the playlist with a hotkey? I can see how to remove currently SELECTED but not currently PLAYING songs. Also is there a way to actually delete the song file also, that would be great.

well, you could select the song that's playing and then delete it. (you can assign global keyboard shortcuts for both these steps, if you want.)

second question: there's a plugin called foo_delete that allows you to delete the files from within foobar. however, you won't be able to delete the currently playing files with it because they are currently playing.

hope this helps a bit.

foo_massdelete will let you delete a playing song (with "Stop and restart playback if necessary" option checked). You can however only do actions on selected items. Use foo_scroll to control focus and highlight (e.g. make currently playing track always the selected track). You can then bind whatever you desire to hotkeys. Should be a working setup for what you want.