I would agree that 2) is indisputable. In fact, they could have been the Fallen that Chihiro was warring against - or, more likely, taking advantage of to war against his opposition.
3), I fear, is laden with assumptions. The most egregious of them is that the Cave could be hidden from anyone with access to the full TF tech base and the certainty that there was something to find. Remember the saying 'half of a secret is the fact that it exists'.
One of your starting assumptions is also debatable. We know that Langhorn's records were hacked to insert the colonists moved out of Alexandria. Removing all traces of a _dead_ TFN officer would have been no more difficult. Editing her personal baggage list would have been even simpler. And a fairly obvious precaution, come to think of it.
Thurgrak wrote:This is a bit sarcastic and I apologise for that.
So no-one thinks it possible that the other Brethren type groups in other enclaves might have adopted a different approach to Knowles's 350 year wait to open the document?
And we seem to have the consensus that the stuff produced by the Hamilcar would have been capable of defeating the stealth tech of something constructed with the facilities of an entire terraforming fleet to be undetectable to known equipment and placed in the optimum location chosen from the crust of an entire planet. Could anyone who thinks that the cave would have been found explain why Merlin isn't using the same tech to see inside the Temple?
And for reference the PICA was listed in Langhorne's "Master Lists" (OAR) which is why Nimue transferred and died. Whatever else (unless Langhorne purged what would based on the capacity of the verifier memory sphere have been a tiny amount of information) that information - ownership of the PICA and presence on the ship at some point - would still be on Langhorne's files so Schuler or whoever was in charge after Langhorne died would have had access to it and a general search in the records for "Nimue" would have found it irrespective of what Schuler or anyone else knew of Nimue before that. I would also argue that IF the search took place the fact there was a PICA and the transfer would make it fairly obvious what happened.
I'm not saying I'm right - in fact I suspect I'm not but unless there is some serious textev I'm missing the following is indisputable.
1) There were multiple enclave groups with the information the Brethren had which includes the name Nimue
2) One of those groups COULD have been found by Schuler or other archangels of the Langhornite faction
3) There's no particularly rational method using demonstrated tech capacities (SNARCs and whatever scanners are on the OBS) of determining small scale power/materials at long range with low power methods through planetary crusts when those objects are highly stealthed and know exactly what to protect against, if there is the OBS should be assumed to know exactly what Merlin (an unstealthed publicly available metallic object with a power plant) is - and why would a PICA be programmed into the OBS as something allowed? The fact the series didn't end a couple of hundred pages into OAR in a flash of light as Merlin was vaporised by the OBS is the best evidence that sensing Merlin's cave was impossible with low power methods.