hi @DataMike ,
The Balancer role is normally added (by default) when the HDFS service is installed,
so the "Balancer" Resides usally in your nameNode , but to make sure where it's assigned you can check HDFS->Instances
then check the role Type , you'll find the role 'balancer' assigned to a host ( usally it's the nameNode ) .
for your second question I guess it's better to use the nameNode just to maintain the architecture since we're talking about checking all the other DataNodes,moving blocks...