Re: Githzerai appearance. I'm playing in a Planescape campaign right now and had my first brush with the Githzerai in more than 24 years. I was somewhat flummoxed to learn that they now looked almost identical to the Githyanki.
The Githzerai's primary soldiers against the Illithid threat are the Rrakkma Bands. While the Githyanki prefer to throw overwhelming displays of military might (including spelljammers and red dragons) against the Illithids, the Githzerai instead prefer small units of hunters using guerilla tactics against their former oppressors. Each Rrakkma bands acts autonomously, as a whole the Rrakkma have little in the way of ties to other sects in Githzerai society, but often they do recruit from them.
The Rrakkma do have their own training methods and techniques, some passed down from one elder to younger recruits, though most of their knowledge is recorded in the archives of the Floating City, in the Lodge of the Rrakkma. The Lodge is a sacred shrine with halls lined with chaos-shaped statues of the greatest of Rrakkma hunters, it's a common ground for many disparate Rrakkma Bands, as it's the closest thing the Rrakkma have to a headquarters. The Rrakkma train in stealth, infiltration, resistance techniques against mental control and influence (which Githzerai are naturally gifted with), recognizing signs of mental manipulation, along with combat techniques like grappling and pack tactics.
Many Rrakkma hunters are rogues, rangers, fighters and monks, but any class serves a purpose among the Rrakkma. The thralls of the Illithids are often valid targets to the Rrakkma, but most seek to eliminate the Illithids without slaying too many thralls as most Illithid thralls (except for Grimlocks) can become allies to a Rrakkma Band. One of the greatest glories a Rrakkma hunter can achieve is the destruction of an Illithid Elder Brain, any hunter who does achieve such a feat becomes a reverred champion in the Lodge of the Rrakkma. The Rrakkma will share their knowledge with non-Githzerai as it helps with their mission to eradicate the Illithid threat. And some Rrakkma bands do have non-Githzerai or non-Limbo natives among their ranks.
In general the Rrakkma care very little for the schism caused by the Pronouncement of Two Skies which lead to the split with the Githyanki. Individual members do hold grudges against the Githyanki, but when there's a choice between fighting the Githyanki or fighting the Illithids a Rrakkma Band will always seek a temporary truce with the Githyanki in order to defeat the Illithids. It was from one of these truces the Sha'sal Khou a sect devoted to the unity of the Githzerai and Githyanki people was formed.
The Rrakkma regularly have dealings with non-Githzerai, they can often be found travelling through Planar Metropoli on their way to other worlds, many travel as passengers aboard Spelljamming vessels, and in the various cities in or near Underdark a Rrakkma Band can often be found. It's not uncommon for the Rrakkma to be seen working with Svirfneblin, Duergar, Goblinoids and Drow as the presence of a Rrakkma band is a much appreciated boon in their battles against nearby Illithid colonies. Rrakkma Bands are less commonly seen on the surface cities of worlds in the Material Plane, as their presence among the surface dwellers is often a bad omen that the malignant Illithid influence has spread too widely, with the Rrakkma Band searching for signs of Illithid infiltration.