1 - does enterprise manager (dbconsole) need to be running on the server of a GC managed database? or just an agent?
2 - if on GC, in the data guard section, we click primary, and then we get a list of standbys, but are unable to click the target name (accessing it), what could this be? the agent is running in the standby server.
1 - the agent yes. but is the agent enough for every possible management feature? or does dbcontrol have to be started/configured?
2 - I mean, that in the stadnby database list, the targetname is not clickable/selectable.
1. Lets make it clear. If you have installed a Management Agent, you does not require any Database Control to be started / configured.
Agent will take care of the metric collection for all the targets in that server.