I thank you all again for your help. I met with the DM and the other player last night and am well satisfied, having met them in person in my home, that things will go well for our group.
The DM recanted, without being asked to do so by anyone, his players-must-play-their-sex edict. He said to me that he'd had male players in the past playing wonton sex-fiend females and that, in an effort to avoid having that happen again, he had imposed the ban.
The "min/maxer" turned out to be a nice fellow who asked many more questions last night in person regarding the campaign world than he did about prestige classes and the like. One of you here on this thread suggested to me that perhaps he was asking the initial min/max questions so he could fine tune his character in order to better roleplay, and my sense (having met him) is that this is indeed the case, and happily so! I was wrong on my instinct that he would turn out to be a poor roleplayer.
And, quite happily, we changed plans at the DM's prompting and decided to play some Scarred Lands, about which all three of us are excited. I myself have never played SL but, MAN, am I hankering to do so.
Lesson learned: Wait to meet someone in person before making assumptions (if you make assumptions at all). Is that difficult to do? Why, YES, it is.