Atarlost Walts Intention in his initial post was to make them a viable choice, not a replacement. I dont think hes outright saying that if you want to use the circuit you must have only one core on your ship ever. Also, that means it must have drawbacks if it straight up out performs a more modulated system, which it obviously does. The point is choice! I'm just stating that only ever running a single core, although possible, is not the best idea in a game where internal damage is guaranteed in a good fight. I like the idea of the circuit chain reacting, but that is a further hindrance on the idea of a single core and encourages redundancy. Not that my opinion on chain-reacting carries weight on the final decision, but i personally would build a double core system regardless of the result.
Yes, the core feeds energy storage near the components, thats the plan. If you start with a full storage then the time it takes to travel a maze circuit doesn't matter so long as you are feeding the storage at a sustainable rate over time. If you are out stripping it's supply, it doesn't matter how long or short the distance is, the issues will be the same, i think.