Speculah:Magical Girls as Devil Pacters
Assuming that Aoki knew the hidden themes of the show while designing the characters (and magical girl outfits), could it be that she based the mahou shoujos in other "devil pacters"? Take Mami as an example. Her use of "Unlimited Musquet Works" and european attire reminded me of Rip Van Winkle from Hellsing, and thus of the german legend/opera of "der Freischütz" (Marksman)
in German folklore, is a marksman who, by a contract with the devil, has obtained a certain number of bullets destined to hit without fail whatever object he wishes. As the legend is usually told, six of the Freikugeln, or "free bullets", are thus subservient to the marksman's will, but the seventh is at the absolute disposal of the devil himself. (Wikipedia)
Her special attack being called "tiro finale" (italian for final shot) just makes it more interesting. That "Schütze" (rifleman) comes from the verb "schützen" (protect), could explain her actual role by Madoka and Sayaka, the new Mahou Shoujos to be.
That was for Mami, what about Sayaka with her knight costume? (Joan of Arc, a saint condemmed UNJUSTLY for being a witch....?) As said, just thinking crazy shit.
Another little thing I noticed is the Soul Gems. While in Mahou Shoujo mode, they are an ornament of their costume (Madoka has a choker, Sayaka has a....bellybutton warmer? That´s clearly not a belt) It seems they are fixed to their bodies, or always in contact with the skin (particulary noticeable by Homura´s design, it looks like a gem attached to her forehand)
But what about Mami? She has her soul Gem in form of a ring. She can dettach it and put it on at will as we see her using it as a witch radar in multiple ocassions. Maybe this one´s too farf-fetched and we should wait until the other girls get their gems, but I find that detail worth mentioning. I will shit bricks if that Gem is actually fused to their bodies.
Editor 2: I think you should sh*t bricks now because they seem hella attached to their skin. Magical girls (Sayaka, at least, and Mami as you said) can transform it into a ring. When they are in Puella Magi mode, yes it is an ornament of the costume. Sayaka's, I guess, works as a navel piercing...? Mami's is attached to her hair accessory. If her soul gem were elsewhere, she would have survived gettiNG HER HEAD FREAKING GOBBLED UP BY CHARLOTTE IN ONE HELL OF A BITE. Though, she would be blind, deaf, mute, and she would be essentially in a coma because, well, she HAS NO BRAIN BECAUSE SHE HAS NO HEAD. So I guess it would be better she died.