No really new vocabulary but if Okrand wrote or vetted this (anyone know?) as he may well have done - 1. it's an official announcement; and 2. notice the absence of a redundant plural suffix implied with {luwIvlu'ta'} on {ghetwI'} - we now have another word for "actor/actress", derived from {ghet}:
(HQ 12.3:8): {Qaq} "behave falsely honorably, behave in a falsely honorable manner" ... is different from {toj} "deceive" and {ghet} "pretend", neither of which has this kind of connection to honor ... {ghet} and {ghetwI'} "pretender" generally do not imply deception, but simply role-playing.
(De’vID, 11/10/2015): At ... qepHom [2011], Okrand said a bunch of things about what verbs take what objects ... One of the words that [Okrand] used to illustrate this was {ghet}. You can say {vulqangan jIH 'e' vIghet".
in addition to {DawI'} derived from {Da} "behave as, act in the manner of" used on this list for years, which appeared in the "Message to Kronos":
qatlh tlhIngan lut luja' tera'ngan DawI'pu'lI'?
Why are your Earthling actors telling a Klingon story? ('u'-MTK)
As for the difference between the two...?