The alt-drag only works for playlists, not albums (or stuff from the soup view) is this intentional?

Yes.

Items in the soup are ordered (by default) by the last field named in this list (from the code). You cannot change this ordering, except for view purposes:

    const TreeRoot soup_roots[] = {

	{ IDS_ARTISTS, "Artists", "artist,source,tracknr", "15,17,21", },

	{ IDS_ALBUMS, "Albums", "source,tracknr", "19,21", },

	{ IDS_GENRES, "Genres", "genre,title", "23,25", },

	{ IDS_YEARS, "Years", "year,title", "27,29", },

	{ IDS_ALL_TRACKS, "All Tracks", "title", "31", },

    };



    const TreeRoot non_soup_roots[] = {

	{ IDS_ARTISTS, "Artists", "artist,title", "15,17", },

	{ IDS_ALBUMS, "Albums", "source,tracknr", "19,21", },

	{ IDS_GENRES, "Genres", "genre,title", "23,25", },

	{ IDS_YEARS, "Years", "year,title", "27,29", },

	{ IDS_ALL_TRACKS, "All Tracks", "title", "31", },

    };

The first stanza is for the HSX-109, the second is for the car player.