I know you were talking about the spawns.
Also on the MMs, you'd want to be powerful enough to kill Petrus, and if you are, it's just a matter of playing smart to kill the guards and angels. Unless you have gas immunity, the MMs would screw you over as well.
And thats where Ivan and his mask show up
Anyway, if you are able to at least give a fight to Petrus, then the rest of the town is just a piece of cake, you don't need MMs all over the town. You only have to worry about taking the archangel before Petrus or viceversa but not at the same time, as they are the only ones that really give a fight once you are strong enough. Oh, and be sure to tame the mystic light frogs before attacking, or fighting Petrus out of their range otherwise as they can be annoying.
About the genie I always wondered the same thing! Is there any way to know if after 1001 nights the genie really stops serving you? I mean, it's crazy to spend 1001 in game days, but maybe there is something in the code...