[quote]How vulnerable would the Forerunners be to time travel shenanigans?[/quote]More vulnerable than the Covenant and UNSC. Slipspace travel in itself is technically time travel. IE: Two ships who travel to the same destination from the same starting location may arrive at the exact same time, but they can measure different amounts of time in slipspace. One ship could measure an hour travel time, while the other measures a 2 hour travel time. Yet they both arrive at the exact same time in space-time. The inverse is true too. Bothe ships can arrive at said destination at different times, but can record the exact same travel time in slipspace. [quote]Also, does the Precursors ability to manipulate technology only extend to technology based off of the Domain or is a case of anything that uses circuitry being børkëd?[/quote]Not at will no. They'd need to devise an external method to take control of technology that is not their own. That is to say, it'd be incredibly easy for them. This is evident by the logic plague.