Thanks for your answer asgm!
I'm only willing use AT-mode on my router(s), if I'm need these to reach the coordinator from my end devices when they are too far away. I want it/them in AT-mode because, im thinking (wrongly?) in AT- mode, if it/they get an API packet from my API- end devices, it/they pass through to the coordinator (API), as it/they got it from the end device(s). Or should the router(s) in API mode too?
My sensors: sadly only my LM-35 is voltage based analog sensor, so with that sensor I could do the direct I/O sampling (because I want printing to the serial monitor at reciving, coordinator side the measurements in human friendly format (text). (BMP-180 and DHT-11 cannot work directly with xbee
) That's why im using Arduino with them. But anyway, that's not a problem to me