In my mind, there are three types of keywords.
Some keywords, like
Harbinger or
Ritual, exist to unify certain mechanics. Once you know what that text in italics does, you can skip over it on future readings. Technically
Archival Drone has four lines of text; I only read three words (
Drone. Interlink: Anthropology.) and I know exactly what he does. These keywords don't necessarily need a lot of support cards (Interlink literally has 0) to justify their existence, but they do need a mechanic. I can't say there are any such keywords I would like to see introduced; it'd be more a matter of identifying a proposed mechanic that could be simplified by using a keyword.
Other keywords, like
Capture or
Infiltration, reference mechanics without actually
doing anything. If a card has the Capture keyword, you know it will likely have something to do with taking an opponent's personnel, most likely into your brig. These keywords replaced 1E's "X-related card" wording, making it
much easier to reference such cards. Similar to the mechanic-unifying keywords, I think we have the bases covered unless we add some specific idea to the game (such as with
Holoprograms).
The final type of keyword is the flavorful keyword, such as
Host or
MACO. These keywords don't do anything on their own. They represent some manner of Trek-sense and other cards reference these keywords. On these, I agree with Charlie. There's very little downside to these keywords, especially on personnel. I agree with Enabran that new affiliation could (and should) bring their own keywords. Other than those, I can't think of any particular keywords that I would want which would not also require quite a few old card updates. That said, I wouldn't have thought of Chef either until I saw it, and in hindsight it seems so obvious.
There are several keywords I would have liked to have seen, but which would require a lot of updates (or even outright reworking of the entire game) at this point:
Chula - 'a dilemma whose title begins with "Chula"' is so clunky compared to what could have been with the keyword.
Clown - Same idea as Chula, it'd be nice to have an official group on these.
other dilemma keywords - A bit vague I know, but I would have liked to have seen dilemmas have keywords which represent the kinds of threats they pose. Examples could include "anomaly" or "creature." Even existing keywords, such as "
Assassin" or "
Q" could have made dilemmas much more interesting.
Nagus. - Like Kai, there's only a handful but they're incredibly important to the affiliation. Zek, Gint, and specific versions of Quark, Brunt and Rom could have it.
Officer: Rank. - Officer is a weird skill, in that most skills are things you
do or
know, whereas officer is something you [/i]are[/i]. I would have preferred it be a keyword, with the associated rank, for captain level and above to keep from getting too into the weeds. Ranks could include (non-exhaustive): Captain, Admiral, General, Thot, Gul, Legate, Colonel, DaiMon, Commander (Romulan equivalent of Captain).
Telepathic. - Similar to Officer, but replacing Telepathy and without any differentiation.
"Save your strength. There'll be another time. The princess - you have to take care of her. You hear me?" -Han Solo to Chewbacca, ESB