This is after a bunch of iterations and bug fixes, so unsure of the repeatability, but now I have functional HBase on top of functional HDFS.
this is still a broken state - the JobTracker and TaskTrackers do not start. this is probably due to CDH4 rather than due to script misconfiguration. the JobTracker doesn't start, but logs nothing into /var/log/hadoop, so will be a little more subtle to figure out - this will be enough to get HBase working.
remove zabbix - too much trouble, change how configuration works to not conflict with source control, fix mysql to allow for new sizes of innodb log files, many other changes