OK, I'll play, Munchkin is a parody game that uses cards dice and a gameboard and is selling extremely well and is the primary product of Steve Jackson Games right now. I own d20 Munchkin and enjoy it, but the Village of Ommlet from the Munchkin GMs Screen was a stale joke back in the 80's and has not improved with age.
The first sentence looks like it was cobbled together from a web search. There's no gameboard in most incarnations, but they do exist in fancy boxed sets, as a way to track going from level 1 to level 10; I got a copy of Munchkin Zombies Deluxe that includes such a gameboard from a convention I volunteered at (volunteers could choose a reward from various donated merchandise), but I gave it unopened to a Munchkin fan. I've played with the original set, several of the D&D themed expansions, the Cthulhu themed one and a ninja themed one, never using a game board - mostly used pennies to track levels.
But d20 Munchkin is a completely different game; an actual d20 supplement, apparently. I've never seen it or its GM screen. A GM screen would be pointless in the card game. (If you want bad D&D derived jokes, you might look at SPI's Swords & Sorcery.)
So now it is your turn. Prove to the readers that you had an interest in Munchkin prior to the negative comment on sex changing in the game.
Readers? I expect everyone else is already too put off by your creepy obsession with me.
You could search and find that I mentioned Munchkin (along with Talisman and the Greyhawk supplement) in a post over a year ago; searching through my old posts would certainly gratify your fixation with me. Heavy-handed effects like changing sex are annoying in role-playing games; they are more appropriate for a no-investment-in-your-character parody like Munchkin. But I am happy to chat about Munchkin in general as long as you would like. Is there something your web search failed to turn up that you would like to know?
The first time I played Munchkin, someone did indeed fight the Gazebo alone; I inferred (and nobody at the table knew better) that it was an inside joke from the designer about putting up a gazebo, but later discovered that it referred to an anecdote about a player who thought a gazebo was some kind of monster (and ended up being eaten by it alone). The "run away" game mechanic to escape a monster you can't deal with was uncomfortably close to the evasion table in original D&D.
Races and classes confer various advantages and disadvantages: elves can gain a level by helping another player in a combat; a dwarf can carry multiple big items and have an extra card in their hand (if I recall correctly). Great strategy to play a curse to force a player to lose their race when they depend on its abilities or an item usable only by that race, and similarly for class. If you eliminated a particular race from the deck because it offends you, then all the treasures usable only by that race are pointless, but at least they could be sold or discarded to power some ability. Eliminating the change race or class curse would also be a more significant change than eliminating one monster, but probably less so than the change sex curse, because players would still have a mechanism to become another race or class (just no way to force another player to stop being that race or class).
I inferred that the "Half Breed" card was objectionable to the original poster as a racial slur; the card would allow a player to have one race card in play without suffering its disadvantages, or to use two race cards and have the benefits and disadvantages of both. So you could be an elf-dwarf half breed; maybe the objection was to the implied miscegenation. The Super Munchkin card is equivalent for classes; we would have called it "Split Class" back when.
And I have in my hand at this very moment (I borrowed it from a serious Munchkin player) "The Official Munchkin Bookmark of Braaaaaaaains" which includes the following text:
You may use this bookmark in any game of Munchkin or its sequels, or Munchkin Quest. It may be used at any time when you are in combat. You may only use one bookmark (of any kind) per game unless you change sex. If you change sex, you may use a second bookmark. You may not use more than two in a game, no matter what.
If you run a Munchkin tournament and ban the change sex curse, you would probably piss off some serious player who has multiple bookmarks, not because they care about changing sex per se but because they want to take advantage of two of their bookmarks if they can.
I had a different official Munchkin bookmark (another promotional goody from a convention) once upon a time that you had to tear in half, declare "I'm digging for gold!" and stick half in the treasure deck; when it came to the top you got the treasure card after it (and the sucker who should have gotten the treasure got nothing). Usable once. Not surprisingly, I no longer have that bookmark.
I think more than a few traditional RPGs would be better off using the quite abstract inventory/encumbrance rules of Munchkin. You can carry any amount (except for the Big item limit) but only "equip" a limited number of each that require a hand or are footgear, headgear, etc. so that their bonuses/effects apply. (But a hand of cards containing potential wandering monsters, curses to inflict on other players, races/classes to change to, etc. would make no sense in a traditional RPG.)