It would be extremely rare for all 3 batteries to fail at the same time regardless of how they were maintained or stored, sounds to me that the hub or charger is now faulty.
The difference in the transmission distance between the 3 different RC's is negligible to be honest. The other differences are more of a deal maker/breaker in my opinion. The N1 is missing the extra buttons and zoom dial that the RC and RC-PRO...