Concerning the Eldar, there will be a lot of them in the Mextil cluster.  Fortunately, their ships make for some very good salvage.<br/><br/>For convenience, here's a quick list of the Eldar cultures and taboos.  Part of the reason that Eldar have such a reputation for deceptiveness is that they have many different cultures, but the Imperium orientaizes them all into one "Eldar" race.<br/><br/>Craftworld Eldar: Arrogant Prigs.  Craftworld Eldar are obsessed with fighting the final battle against Chaos, and don't value any lesser being in the slightest unless it helps them fight Chaos.  A death fighting the final war which results in a quick download into the infinity circuit is a good death.  Anything else is an abomination.  An Eldar deprived of his or her soul stone, or hearing even rumors of Eldar soul stones, will do ANYTHING to get them back.<br/><br/>Exodite Eldar: Arrogant Prigs.  Exodite Eldar focus mostly on luxurious lives full of leisure, often reincarnating themselves into many different species and practicing sublime mastery of the arts of war.  Exodites absolutely refuse to leave their home planet, and will do anything to spare their world from serious ecological damage.  Each exodite world has a "World Tree" which acts as the infinity circut of the entire planet.  Exodites fight to defend their world tree with a ferocity that is said to frighten even Khorne.<br/><br/>Dark Eldar: Arrogant Prigs.  Dark Eldar fly out of the webway and capture prisoners for their own sadistic pleasure.  Unlike other Eldar, Dark Eldar are happy to throw their lives away in stupid ways, even taking great pleasure in doing so.  Dark Eldar suffer from chronic backstabbing, even though they have a strong taboo against betrayal while in realspace.  Death is nothing to a Dark Eldar, and pain arousing, but shame and political loss are absolutely terrifying to the Dark Eldar.<br/><br/>Eldar Corsairs: Arrogant Prigs.  Eldar Corsairs are true rogues, living independently in their starships and using a fusion of the technology of every Eldar faction they can trade with.  The corsairs are as unpredictable as they are deceptive, and aren't bound by the same rigid codes of behavior that other Eldar are.  Eldar Corsairs still rely on infinity circuits and soul stones, but don't have the obsessive need to hunt for lost soul stones and infinity circuits that Craftworld Eldar have.  (though they'll be interested in such things if there's a good opportunity to trade with a craftworld coming up soon.)  In many ways, Eldar Corsairs are the mirror of Rogue Traders in Eldar Society, but they often sail for fame, rather than wealth.<br/><br/>Eldar Harlequins: Arrogant Prigs.  Eldar Harlequins worship the one living Eldar god, and spread his gospel through the magic of interpretive dance.  Despite being simultaneously street performers and missionaries, Harlequins are some of the greatest warriors in the galaxy, using their acrobatic techniques to move with grace and speed, and taking advantage of their diplomatic immunity to trade with any Eldar society they please.  Harlequins possess a certain degree of unique technology, and don't have the same kind of readily apparent psychological weaknesses that other Eldar have.  Harlequins are the most dangerous of all Eldar, but their numbers are fortunately small.