Just what the title says really.
A multimedia file (movie/audio-cd/whatever) may be stopped by simply exiting the media player (windows media player/vlc/Qt/...) instead of going through the whole rigamarole of hitting the stop button (or File/Close menu). I find myself wondering whether these commands aren't vestigial.
Could simply exiting the media player damage the media/computer?
No.
Typically, all a media player does is just play the file, i.e. get the file handle from the system and read from the file's data. In most cases, data is even pre-cached from the disk into main memory, so playback isn't affected by disk access from other programs, and your hard drive won't always be read from.
Anyway, a media player typically does not write to the file, which means that your file won't be touched. Even if the process quits unexpectedly (for example by force quitting it), the operating system will just release the file handle.
You can even test that. See if any of the file's information changes (e.g. timestamps, "modified" time) when you play it. No decent player should do that without you actively changing information and pressing a "save" button. There are some players that behave differently though.*
* For example, iTunes will automatically update ID3 information in MP3 files once you change something in the "Info" dialog. This is in my opinion not how it's supposed to work, but these file saves only happen once, which means that you most probably won't just "lose" a file if something goes wrong.
It shouldn't.
The the player should be simply reading the file and thus not making any changes to the file so simply closing the player should not affect the file in any way.
Similarly the stopping of the playback shouldn't affect the hardware in any way either.
I say shouldn't as there might be a badly written media player that does modify the file in some way.
