we've all looked up alien girl porn once-thrice-pretty much anytime, from star wars (those sexy twi'lek girls); even to the point where something that is completely not human (xenomorph from aliens, or a slightly humanoid insect girl with little to no human features [mainly no human looking face but relevant body parts, i.e arms, legs]) was sexualized and art made of it to where even that became fappable and sexy

I am a person who likes those kinds of porn from time to time (if the game I'm playing isn't interesting enough atm), and reading the F.A.Q for story proposals says "no copyrighted work"; I assume it would mean no sexy girls from the star wars franchise or any-other sexy girls from whatever franchise that is no longer protected by copyright (if such a thing is even possible); I know this next bit is somewhat already being worked on, but if XStoryPlayer gets to the point where we can mod our own 3D models into it, create our own stories; would it be possible or allowed for something like a xenomorph to be fuckable in XStoryPlayer (as an example of such, I turn you to furaffinity artist max tony, and the flashes he does of aliens with female bits getting fucked; i.e female elite from halo, female jackal from halo, the relavent female non-humans from skyrim, other non-human female sex stuffs made by other 3d porn people, etc...)

Hmm...A twi'lek would be pretty fun in this game with their lekku bobbing and swinging around.

You'd have to modify it enough. I think it would be more rewardable (though it would demande more work) to design new creatures and make a story out of it. You wouldn't have any copyright issues this way.

so unless it got redesigned and included with the game in a future update (enough to bypass any copyright issues); it could be possible to mod a female enough non-human into the game through a mod story (you end up sex'ing a xenomorph) as long as that story is completely free and not pay-to-play in anyway shape or form?

Well, no... whether you charge money for something or not, whether you give credit or not, it infringes upon copyright. While the odds of being sued in such a situation are small, one must not forget the FOXing of the fanmade "Aliens Quake."

Too bad i wouldn't be able to use these twi'leks, becuase they will always remind me of this
Who would think... damn Farscape is about to ruin my sex life!

Anyway, i would be careful about any posibilities of copyright infringement, i think nobody here wants the game to gain attention that way.
I have seen various mods for various games, using various characters/items/properties from many movies, and most of them had one thing in common - once the mod got far enough to start looking really good, gaining audience, almost all of them had to stop because of some copyright stuff.
From what i seen so far, it depends - sometimes they let you be, sometimes they'll ask you to stop (and sue if you wont).

Make a near replica of the species of your choice and name it something else. Light saber, light sword, laser sword, etc etc. All the same thing, just different names and designs, really.

Though, I do question if you can even copyright a species. Fantasy or not. Generally, in the research I've done in the last half hour, the copyright notices that Lucas Arts/Films give out tend to refer to characters, not races. I think if you simply avoid using actual character names, you're pretty much fine.

http://copyright.gov/help/faq

Lucas overlooked a ton of stuff, actually. But now that it's all owned by The Mousefia, who are crazy protective of their property, I wouldn't risk it. I say let someone else be the test case first.

Hmm, sounds reasonable, and would make sense. Also, now when i think of it, there is a lot of species/type addons/mods still floating around, while those mods that got "ditched" were more like a total conversions even using the character/story names, so you are probably right.

Well, looking at that PDF (See Circular 1, Copyright Basics, section "What Works Are Protected."), i am afraid that the "looks" of a game/movie character, even if you call it whatever else, might be exactly which is protected by copyright.

How i understand it, if you make a MOD depicting twi'lek girl, even if you'd call her "a-generic-girl-with-tentacles", the graphics depiction in the game would fall right into the category of "pictorial, graphic, and sculptural works".
...then again, i am NOT a lawyer, so my interpretation of the text may be wrong (not mentioning its just a small part of one paragraph from a whole book).