It is done on a timeline in an environment called the Montage, where you can also place CD-tracks on different tracks (and much, much more!). I don’t think there is a limit on crossfade time - it would surprise me if there is. And CD-markers can be placed freely (in full Wavelab, that is). Also, Audio in Pauses is supported, which allows you to keep audio running between a track’s end marker and the next track’s start marker (live CDs for instance).
Just give the trial version a go!