[FWB]

circulating coolant when engine is off wouldn't do much without fans also running in off mode, this may be enough to deaden a battery and leave you sit.
i have only run the electric pumps with drag cars not on the street. the csr's are the easiest to deal with. but the electrical aspect is some thing to consider. i had to beef up the alternator to handle msd's appetite and the distance to the trunk didn't help either. with the added useage of fans and a water pump on battery only seems like it could pose a drain on battery.