Sorry, I'm late. I took my time researching the info about the races. GR stands for Galactic Rim. HE stands for Horologian Empire. AU is the Authority (AU is used instead of A, which is being used in ASW, Inferno and other FS2 campaigns).
Let me explain the races involved. The Galactic Rim Worlds is made up of the coalition of alien races from another galaxy allied with the Horologian Empire of the Milky Way. The technological level of the GRW is higher than that of the present day Earth, but inferior to the Authority.
The Authority is a highly diversified and technologically-advanced alien force that controls and shapes the cosmos how they see fit. The Authority aliens use advanced shields (which covers not only their fighters and bombers, but also the capital ships, installations, sentries, freighters and transports), beam weapons, cloaking devices and other technologies that defy physics, like the Shivans of the FS universe. The Authority's main purpose is to restore order to the universe by any means necessary, including exterminating races that do not submit to them.
I'll put this on a wiki later on as soon as I've finished the species.tbl file, which is still in development.
Speaking of ship models and textures, retexturing the Ancient ships a bit to make them look more unique and to prevent people from receiving the ASW vibe seems good, because I think it's a good idea to take advantage of FS2_Open's latest features, as well as forthcoming ones such as parallax occlusion/relief mapping and possibly making full use of dynamic screen-space ambient occlusion. Another way to stop giving the ASW vibe is to remodel everything - perhaps in full Collada format in which DahBlount and I am currently working on it. I know these may seem time-consuming, but due to the large number of outdated models, especially the Pylos, Minos and Androgeos (both are used as the GRD Adhipa, the GRBs Svaamin and the GRJ Viraat), I feel it is neccessary, if I want to take advantage of most of FS2_Open's latest features, including Swifty's deferred lighting and soft-shadowing, parallax occlusion mapping, displacement mapping, tesselation, real-time screen space ambient occlusion, and so on.
Also, I think ship models should possess shields, much like those in Dimensional Eclipse. I have gained experience from Blender, and I think I can do it.
I've got an update on its setting, let me re-iterate Lepanto's suggestion on crossing over any non-FS properties. The 2012 Total Recall remake's narrative is techno-chemically induced
while its main character Quaid was in the artificial memory-chair at Rekall, so it is highly unlikely there will be a crossover. However, this mod contains elements derived from it. For instance, there are news programs from the chemically-devastated Earth, picked up by GRW and Authority ships in space alike as transmissions traveling at the speed of light in the vacuum. These programs range from the massive military buildup at the UFB to celebrations at The Colony, the deaths of UFB Chancellor Cohaagen and his forces and the destruction of the Fall. In conclusion, judging from the year The Fall was completed ten years before the film, the Orion Engagement prequel campaign takes place in the Earth year 2116, and the main campaign itself will be set in 2121. Sounds straightforward?
Anyway, it's not like Ancients vs. Shivans in the FreeSpace universe. It's a galactic coalition of freedom-fighting aliens vs. an oppressive alien government bent on universal domination.