Needed: Casting Director

Writers find inspiration in weird places; many writers of drama like to know who will be acting or singing the pieces they're writing, so that the performer can inspire the role. I thought I'd jot down here the principal roles from the immense cast list of the proposed MONSTER GOD Wagner film, and see if anybody reading this blog has strong feelings about who to cast in which role. (I've been objecting to Richard Burton as Wagner, whereas Stephen Wadsworth has been praising Trevor Howard's performance as Wagner in the LUDWIG II movie to the skies.)

So who would you cast as:

RICHARD WAGNER

HIS WOMEN:
Minna (his beautiful, unhappy first wife)
Mathilde Wesendonck (his inspiration for Walkure and Tristan, the beautiful wife of his patron)
Cosima (his second wife, must transform from ugly duckling teenager to fearsome high priestess)
Johanna Geyer (Wagner's short, sarcastic mother)
Cacilie Avenarius (his pretty little sister, always full of hatred for Minna)
Wilhelmine Schroder-Devrient (the mezzo soprano who turned him on to opera, who created the roles of Senta and Venus)
Malvina Schnorr von Carolsfeld (his first Isolde, later a raving banshee and thorn in his side)

HIS ENEMIES:
Giacomo Meyerbeer
Holtei (the slimeball theater/brothel manager in Riga)
Luttichau (the obstructionist bureacrat theater manager in Dresden)

HIS FRIENDS:
August Rockel (the bespectacled assistant music director/revolutionary)
Franz Liszt
Mikhail Bakunin (the hairy, bearlike Russian anarchist)
Theodor Uhlig (the A&F-model violinist and 'water cure' enthusiast who dies so young)
Karl Ritter (Wagner's likeable young sidekick who gradually finds himself and leaves Wagner)
Hans von Bulow (Wagner's talented amanuensis and champion who sacrifices his own family to Wagner)
Otto Wesendonck (Wagner's pliable patron and Mathilde's whipped husband)
Peter Cornelius (the talented young composer who gets out from under Wagner while he still can)
Friedrich Nietzsche
Ludwig II

HIS DOGS
Rauber, Peps, Fips, and Pohl

And then, what film actors would you cast (lip synching or just acting) in the filmed sequences from Wagner's operas? We'll need a Dutchman, a Senta, a Tannhauser, Venus, Elisabeth, an Alberich and three Rhinedaughters, Wotan, Brunnhilde, Siegfried, Mime, Loge, a Hans Sachs, Beckmesser, Walther, Eva, David, and a Gurnemanz. Or: should we have recognizable characters from Wagner's life starring in his theater-of-the-imagination opera fantasies (ie he himself plays the Dutchman, Tannhauser, Alberich, Wotan, Sachs, Gurnemanz, and so forth...)?