Your posts mistake precognition with the result of planning and the affects of unintended consequences.

The trail seems subtle, but you fail to see that there are elements in this trail that don't require any one specific talent: someone with sufficient skill in interrogation might have uncovered this, someone with sufficient skill at heraldry and history might have uncovered part of it (in fact someone did), someone with the Delving skill might have detected poison, someone with skills with poisons and alchemy might have detected and identified the poison, etc.

If Graendal wanted someone dead, there is nothing preventing her from Travelling to the location, eliminating the target, and obscuring her escape path so that it can't be traced. She specifically chose a method that could be detected to get his attention, and direct his attention to a particular place. She has shown her willingness and capability to do this - that is how she collected so many members of her collection, so what surprises me is that you seem to think that she doesn't have the temperament to personally make sure her headquarters remained hidden, leaving it up to other agents.

The problem with your line of reasoning is that you make this seem a requirement, when they are not. It wasn't necessary for any one of those skills to be present in one person for her trail to be discovered, but it was sufficient. The fact that Nynaeve had all of these was a coup. Perhaps Rand showed up earlier because of this combination of abilities, and this is what may have lead Graendal to weave a hasty Compulsion on Ramshalan and flee.