The Phoenix-Hive storage handler as of v4.14.0 (CDH 5.12) seems buggy. I was able to get the Hive external wrapper table working for simple queries, after tweaking column mapping around upper/lower case gotchas. However, it fails to work when I tried the "INSERT OVERWRITE DIRECTORY ... SELECT ..." command to export to file:
org.apache.phoenix.schema.ColumnNotFoundException: ERROR 504 (42703): Undefined column. columnName=<table name>
This is a known problem that no one is apparently looking at:
https://issues.apache.org/jira/browse/PHOENIX-4804