...Regarding Genoveva; if one approaches it without the seemingly obligatory post-Weimar prejudices, one may discover much of worth. The ability to rattle window shades is not a proper gauge of profundity 
I believe the libretto of Genoveva is another product of Wilhelmine von Chèzy (of Rosamunde and Euryanthe notoriety). However fine the music, the plots and actual writing in her plays has been described as pedestrian at best, and rarely at its best. I suppose if you're just listening for the music and don't understand the words you might actually enjoy it more.
The libretto is the composer's and Robert Reinick's, iirc, it was Wagner's offer to help with it that started the rift between Wagner's followers and everyone else.
This is my first post and I take the chance to mention that is was pieces like this (Das Paradies und die Peri, the Chèzy operas, Fierrabras et al), i.e. the "Sung's Unsung" that drew me into discovering these composers so very mentioned in this forum. Living in Brazil, almost every German opera is an "unsung", so when one thread pulled the other, Genoveva gave into Fierrabras, Der Freischütz called Der Vampyr, I was suddenly in shock of all the awesome music "the establishment" had turned their back to!
Even Beethoven has unsung music! I can't get the dervishes' chorus from Die Ruinen von Athen out of my head, it is so d*mn good, but (alas!) unsung.
I LOVE the pre-romantics and romantics (up until Bruckner and early Mahler), and my religion is the one which the Pope is Haydn. Bach and Beethoven complete the holy trinity and Schubert gives it life! So imagine when I find out there is a whole deal lot more symphonies out there to be heard, Ries, Kalliwoda, Gade, Onslow, Rufinatscha, the list goes on and on! Suddenly we realize why Beethoven was, in fact, the greatest: none of this music is on par with him, but they needn't be! They are fantastic pieces of music on their own, Ries' finales brighten even the darkest of days, Kalliwoda's make the heart race and even Czerny, hated by many pianists as that wretched set of exercises, has a lot to offer!
I'll stop here, or else I'll go on forever!