Pardon My Klingon: Played straight in a number of cases – zakhrehs, for example, while glossable as, is not entirely cognate to, English barbarian – but played even straighter for words that aren’t expletives, but whose English gloss is too long to use in conversation, like valessëf, or valxíjir. Or it’s not-really-an-expletive shorter form jír, perhaps best glossed cojones.
Oh My Gods: Occasionally played straight – although usually invoking one eikone or their attributes by name, rather than a generic exclamation. (It helps to be specific.) Not, however, seen in curse-word type invocations – that tends to be invocation of entropy or its aspects, the canonical example being “Shit and waste heat!”
Luke Nounverber: Averted. While the third name, the attributive name, is often of Nounverber form, attributive names generally are epithets. Not all of them are to be taken strictly literally – there is some “mere puffery” going on, especially in, say, foe-names – but enough are that it is perhaps less than wise to test the point.