Braddoc said:

Adpets have always been a tough sell to most players (there is a thread on that very topic currently in the main DH Forum section); an Alternate Rank that makes them substantially mose useful to an Ordo Xenos team can only help, i.m.o.

Braddoc said:

Standard Guardsmen kill xenos the same way they kill everything else: through overwhelming numbers. But the fluff has always made references to elite xeno-killing specialists with skills beyond those of rank-and-file Guardsmen; the tabletop game made this fluff part of the rules in 4th Edition, which added a Xeno-Fighter Doctrine option to I.G. armies.

Braddoc said:

Off the top of my head, in addition to a Xenoarchaeologist and Xenofighter, and a xenotech specialist like you mentioned, I could see some kind of Diplomat option that negotiates with other cultures, including xenos (yes, it does happen in the Imperium, despite what the Adeptus tells the unwashed masses…), plus a buch of Radical options: humans raised by xenos (a la Stranger In A strange Land), mad scientists who illegaly graft xeno organs and limbs onto humans, and some kind of Cold Trade specialist…

Plus, more fluff: info on the Calixis Deathwatch, more details about the Yu'Vath, the former rulers of Dread Calix (including examples of their ruins and technology), and additional Cold Trade material, ideally including a sample cartel with key npcs.

Crunch-wise, can we ever have too many examples of xenotech? Weapons, computers, vehicles, drugs, toxins, viruses (both organic and cogitator), specially bread guard/servant beasts, etc.

Rules for including a Deathwatch Killmarine in an Ascention-level party for those who don't also play Deathwatch would be appropriate.

The core, though, would have to be more xeno stats! The Radical's Handbook mentions the Calixis-specific Morgauth ('scavenging reptilids'), Xenarch ('of the Northern Rim'), Draethi ('dark alien race'), Q'Orl ('a particularly insidous insection race'), Fra'al ('merciless, highly psychic'), plus a mercenary army called the Cortax (I assume it's a group of various races, and not the name of a destinct race in itself); I'm not a big fan of repeating the same creatures between different WH40KRP books, but I wouldn't mind combining stats for Loxatl mercenaries (from Mark of the Xenos), Sslyth mercenaries (from Koronus Bestiary), and Kroot mercenaries (from various Rogue Trader and Deathwatch sources) in one volume. -And Hrud, with their focus on stealth and warp-based technology, would be a good fit for DH.

And of course, space permiting, a module. Not everyone likes the practice of including mini-modules in Sourcebooks, but, since nearly every DH module focuses on fighting heretics  and/or daemons (Maggots In The Meat is the only exception I can think of), I think a xeno-focused module would be a welcome novelty.

Tell me with a straight face that you wouldn't buy this book…?