If you will call the start script manually, the service will be monitored only if the monitoring was enabled already. In that case however - if the process is stopped, monit will detect it and will try to restart it automatically, so if you monitor some service via monit, you should use "monit stop <service>" and "monit start <service>" to disable/enable monitoring as well.
The default credentials should be changed for obvious reason - they're well known and if somebody will have user account on your machine, he may try to connect to the monit http gui (as he'll be on "localhost") and can try the default credentials. It is better to change both the username and password to some custom value.
I am a bit confused. Even if I start manually using ./startDaemon.sh monit is monitoring it right please correct me? Another thing do you want me to change this (you should change the credentials to something else then default "admin:monit") any reason? If I dont enable it does not work right?