The desire for other types of random play is brought up frequently. So it is on the wish list.
In the meantime, you can accomplish most of what you want by just making a temporary playlist with just the Artist you want, or just the Album you want. Playlist entries don't have to be individual songs, you can add and Artist or an Album, too.
I was under the impression that global random play is supposed to work. With Random turned on (and Classical Mode turned off), select a song directly from the track list for a particular album in the lower right corner of the original WebUI. When that song is finished, the next one played should be chosen at random. If I have this wrong, somebody please help out.