Holy crap, yes! I will gladly steal your creativity wholesale plunder this for ideas offer my opinion as you develop it. Sounds like fun.
Rodrigo offers great advice. My Dread games never go as expected, which is most of the fun. I try to organize them like a 3 act play in terms of pacing, and that seems to work fairly well.
I am more than happy to have my ideas
stolen, er...
plundered, er...critiqued.

Seriously, if folks like my ideas enough to swipe them for their own games, I'd be thrilled. That's part of why I want to put my ideas up here, and get people's input...to make it into a scenario that works not just for me, but for other folks as well.
I posted some stuff about my ideas so far over on the tiltingatwindmills.net message board, but I'm going to go ahead and copy the info here, so folks here can look it over and give me thoughts.
First, a post about the overall premise of the scenario...
The scenario is a horror western, tentatively titled "The Majestic Seven." The plot is inspired by the computer game "Nocturne," the novel "The Haunted Mesa," and Hopi and Mesoamerican mythology.
The very basic outline is that the PCs are seven people of various western genre archetypes, who are all on a train traveling to (or through) the town of Majestic, NM one night. Just outside of the town, some sort of accident derails the train, and these seven characters are the only survivors. They will be the heroes (and some of them also the victims) of the town of Majestic, thus, the Majestic Seven (obviously a play on the Magnificent Seven.)
They make their way into the town, and discover it seemingly deserted. Eventually, however, they will discover the possessed/zombified husks of many of the inhabitants, and will need to fight through them to survive. They are the result of attacks by spider-like humanoids from the Hopi "Third World"--a previous world to this one (the "Fourth World") which fell into wickedness and death, and which Hopi myth says the people of this world "climbed up out of" to escape into this new and better world. I am also associating this "Third World" with the Mayan underworld Xibalba, which was supposedly inhabited by a race of beings who worshiped death. The lords of this realm are the Twelve Lords of Xibalba (also known as the Twelve Majestics, in my scenario) and they are ruled by the two greatest of them, known as One Death and Seven Death. For purposes of my scenario, it is Seven Death that is responsible for the troubles the PCs are dealing with. Thus, he is the seventh Majestic...or, Majestic Seven.
In any case, in the Hopi myths, all life was created by a goddess known as Grandmother Spider (or Spider Grandmother, or simply Spider Woman...but I'm staying away from that last one because it sounds like a superhero.) They initially inhabited the First World, but most of them fell to wickedness and evil, and so Grandmother Spider led only the best of the people up into the second world. This was repeated into the Third World, and finally into the Fourth, with the people undergoing physical transformations with each migration. For purposes of my story, the children of Grandmother Spider looked much more like spiders in the first world, and have gradually become more human with each ascension, thus the inhabitants of the Third World below this one are horrifying spider-humanoid creatures.
Somehow Seven Death and his Xibalban spider-demons (known as the Anasazi--or "ancient enemy") have found and opened the "sipapu"...the hole through which the people first rose up into the Fourth World from the Third, and are making their way through, trying to open the way for Seven Death to come through and extend his evil domain across the earth.
So, the escalation for the PCs is, they face and fight the zombie-husks of the townsfolk, who have been implanted with young Anasazi parasites, so they can grow to full form here in this world. Then, they discover and have to fight a couple of full-grown Anasazi--the ones responsible for what happened in the town. Finally, they have to face and stop Seven Death, and close the sipapu. I am thinking that the story will take them through town and out the other side, to a nearby mesa with a recently uncovered ancient Hopi kiva (a Hopi ritual room) where the sipapu is located. I'm thinking maybe a series of caves and tunnels in/under the mesa to get to the kiva, and that's where they deal with the Anasazi. Then through the sipapu, to the Third World, where they confront and (hopefully) defeat Seven Death, back out the sipapu, and close the door behind them. (Or rather...whichever of them survive do.)
Ok, so that's the overall plan. What I need now is advice and suggestions for breaking it down into acts, and some events to throw into it. Right now I'm thinking "Act I: Zombies..." (set in town, dealing with the husks), "Act II: ...And Spiders..." (set in the desert/badlands and the caves/tunnels, dealing with the Anasazi), "Act III: ...And Gods, Oh My!" (set in the Third World, and dealing with Seven Death.) But I'm not sure if that sounds too big and sprawling, or what. Any thoughts would be appreciated.
The other thing I need to figure out is exactly what the Anasazi are doing, besides just growing more Anasazi in town, what Seven Death's specific goal and plans are, how the PCs stop him, and how they close the sipapu.
Anyway, that's it for this post. I would love to hear any thoughts, ideas, or comments. I'm going to follow this up with another post going into what I have so far for the characters.
Thanks for your time.
Best,
~~~~Random