Can someone please explain the difference between...

[yellowroad23]

ticked/unticked songs (I see that when layout is Track Detail)
- sign or blank space marked songs (I see in Now Playing)
when opening Edit window "Exclude from playback" options
   Full ban (I use last.fm but when I tried full ban on duplicates it marked the other song as banned too)
   Only when shuffling

What does each action mean/do?

When the song I don't want to listen anymore or these days (but don't want to delete) comes on, what should I do with it? With duplicates too. And if I mark them certain way is there a way to see which songs are marked that way?

[psychoadept]

Welcome to the forum!

Read through this thread for an explanation of the check marks/tick marks: http://getmusicbee.com/forum/index.php?topic=12641.0

A "-" sign in that space in the now playlist means the track will be skipped.  A banned track will always have this sign.

I'm not sure about the duplicate thing, could be a bug?  If you are on the Latest Update (http://musicbee.wikia.com/wiki/Latest_Update), maybe you could provide some screenshots (http://musicbee.wikia.com/wiki/Screenshot) of the problem?  "Only when shuffling" is hopefully self-explanatory?  You might use that, for instance, if there are a set of tracks that go to together and you don't want them to play separately when you have shuffle turned on.

A full ban in the tag editor (or right click > Rating > Ban) is what you want to use if you want MB to totally ignore a song.

[yellowroad23]

Thank you for the reply, this has been bothering me for quite a while.
When I mark a song as banned it shows up on http://www.last.fm/user/--your username--/library/banned list and last.fm only knows what Artist-Song you banned not from which album I guess. So after some time, I restarted the player cause I was impatient, it syncs back to MusicBee and marks banned every song with that Artist-Song name no matter the album.

Is there a way to see which songs are marked  "Only when shuffling"?

[psychoadept]

When I mark a song as banned it shows up on http://www.last.fm/user/--your username--/library/banned list and last.fm only knows what Artist-Song you banned not from which album I guess. So after some time, I restarted the player cause I was impatient, it syncs back to MusicBee and marks banned every song with that Artist-Song name no matter the album.

Oh, I see.  Yeah, I can see how that would happen.  Unfortunately, I don't think there's anything MB can do about it.  What I suggest is that rather than banning duplicates you use the function in the duplicate manager to mark them as duplicates and send them to the inbox.

I don't know of an easy way to find "only when shuffling" tracks, sorry!  Could be a wishlist item.