I have no idea what a "mini itx M1200" is

I would assume the display screen is "mini" ..... if this is the case, you might not be able to see stuff, although you can play around with fonts, etc.... to get it how you like it. It also allows for 1, 4, 9, 16 and 25 album covers to be displayed at one time ..... for small displays you probably want to use 1 or 4 per page.
Yes, interfacing with a trackball works well. The software supports dual-screen monitors but it is not mandatory .... it works well on one screen as well. I would recommend configuring about 10 artists with album/songs in the correct directory structure and then try out the software to see if it has what you want.
Also, knowing that videos might not be as clear as the ripped mp3 audio file, my software allows the video and audio file of the same song to exist in the same directory location at the same time. You then always have the option of playing the video or audio file, depending on what you want to listen to. Of course you can set an option to default to giving videos preference over the audio files (or vice versa)
Anyway, try it out and see what it has in it ...... there is a lot of stuff. I created it since I have tons of music videos.