it would be great if you could edit the file tags in the playlist view, without opening the "song properties" dialog
It's not really in the plans currently, I personally like to separate edition and general usage.
The stars column might come sooner as there has been a few people asking for it. Though I honestly almost only change the rating of a song when that song is playing, and for that there is the Stars widget, and for the few other times there is the context menu (in particular you can right click on previous to get the previously played song, and then right click on one of them to get its context menu). So I wonder how useful it would be.
It's just a feature I got in the habit to use with other players. I agree with you there's no need for an inline editing of the rating, as there are so many options already, but it can be useful for some quick corrections to the other tag fields.
Anyway, i can live without it