i can answer a few of these.
I DONT know if it can play .mkv files
I DONT know if the music player supports .FLAC files
I DO know it supports flash.
I DO know you can play the online version of Minecraft. (the old version that is web based)
I DONT know if it can download torrents, since all programs have to be downloaded via the google store, and i really doubt there is a torrent program on there.
I DO know you can unzip zip and rar files and view them on Google Drive.
Hope this helps a little.