Unsure, never played factorio before, but in mindustry each different "CPU" can execute different scripts to utilize their surroundings. I'd imagine that's more "efficient" than eking out a logic using gates?
Depends on your persistence. I've seen a full "mall" (factories building factory items) that dynamically built requests from scratch; no queued items. I've also seen delivery systems which will send a train with the requested items from your central base to your current location.
