It sounds like Okrand has done some work to explain how one might express the irrealis in Klingon. I’m ignorant of that explanation. Forgive me, if I’m digging at something that I should just be accepting. I’m honestly trying to understand this mechanism.

The explanation was given to us on the list by Lieven on November 3, 2016:

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For a statement that's counterfactual (or "irrealis"), a phrase with the verb jal ("imagine, envision") is used: ... net jalchugh ("if one imagines that…", "if it is imagined that…"). For example:

tlhIngan SoH net jalchugh, qagh DatIv
This is "If you were a Klingon, you would enjoy gagh" or, literally,
"If one imagines that you are a Klingon, you would enjoy gagh."

The implication is that you are not a Klingon. Compare:

qaghwIj DaSopchugh, qaHoH
"If you eat my gagh, I'll kill you."
qaghwIj DaSop net jalchugh, qaHoH

"If you were eating my gagh, I would kill you"
(literally: "If one imagines that you are eating my gagh…").

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The way we used to do it was: {muleghpu’be’ ‘avwI’, vaj QaQ ghu’.} "The guard has not seen me, thus the situation is good."

We could also use a rhetorical question, as is common in American Sign Language: {qatlh jIQuch? muleghpu’be’ ‘avwI’.} “Why am I happy? The guard didn’t see me."

If we want to talk about bad situations instead of good ones, {muleghpu’be’mo’ ‘avwI’, ghu’ qab vIjunta’.} "I have evaded a bad situation because the guard has not seen me."

Sticking closer to the original suggestion:

{muleghpu’ ‘avwI’ net jalchugh, ghu’ qab jallu’pu’.} "If one imagines that the guard had seen me, one has imagined a bad situation."

Now, the bad situation is pretty obviously the one that has been imagined. I’m not talking about the event of imagining the situation. I’m talking about the situation that one has imagined.

So, enlighten me. What do I have wrong here?

Just that none of your sentences involve irrealis. They all have to do with factual or conditional statements. Irrealis is about hypothetical or counterfactual statements.

-- 
SuStel
http://trimboli.name