The "Gateway" role is merely an indicator that Cloudera Manager should distribute client configuration files to that host for that service. A hive gateway will ensure that /etc/hive/conf is populated with the necessary configuration to run hive clients on that host. Since there is no running gateway, the status will be None and that is expected.
The parcel files shouldn't need to be modified and are expected to be static.
Cloudera Manager does use those files to generate configuration files for servers and clients based on defaults and on your configuration in CM.
I know you ran into some trouble, but I think all the work you did to troubleshoot goes a long way to an understanding the concepts of CM, services, roles, and client configuration :-).
Please confirm one time in below fields value what i commented:-
<value>com.mysql.jdbc.Driver</value> //this is metadata db
<value>hive</value> //this is metadata db username
<value>mypassword</value> //this is metadatapassword