I am sorry... I like your Idea about class specific sex groups... But... Assassins can be either male or female... I also think that we aught to have EVERY class either sex... Because A priest can be either Pirates can be either... Almost anything can be either. THere should also be Sorcerer(Sorceress) Wizard(Witch) Ranger, archer, beatsmaster, druid, Paladin, warriors, soldiers(male only), bard, barb, lyrist, Necromancer, Amazon(Female only), Dark knight.
As well as all of these classes there should be races... And after I specify the races I will tell you how they fit to Diablo world.
Human, half elf, half orc, halfling, Orc, Elf, Sahauigan, Drow, Centuar, (Give or take a few more) And these would fit in because what we have seen of the diablo world is just the human area of the world... THe west. There is the rest of the world out there.. Possibly with much more races.. And on top of that they could have an evil so large that the troubles uncompass the entire world and everyone much drop thier fueds with eachother and fight together against this evil. an top of all that... I have just one other thing to say.
Icewind Dale was based off of Advanced Dungeons and Dragons Second or third edition was it not? In that it is possible for people to gain more attacks per round... And that is bassically what D2 has... Only they have weapon speeds and possibility to have faster attack rating.. I think that EVERY class aught to be able to specialize in any weapon. So that they are more powerfull in a specific weapon than they would otherwise be... Faster and more powerful.
I also think there aught to be some spells that every class can use... Called common spells.. These would be found in the form of spellbooks like in D1 and they should be tradeable... And certain classes can use common spells better than everyone and some people would be weaker... Namely soldiers and centuars would use it minimally. and sorcerers(sorceresses) and Wizards(And female equilavent) weould be the most powerfull with common spells and get them to higher levels.
we should have more stats as well. Like Constitution... And Charisma. Those are very important.. But D1 and D2 never had them. Oh well.. I am done for this post for now.. I may post later.