You're welcome! To answer your additional questions:
Re: 1: The
admin-console-elasticsearch cluster is just the "ES Admin Cluster" (#1 in your list at the top). It does not include the logging cluster (there is no logging cluster in alpha4, yet). In beta1, an additional cluster will visible in the Cloud UI, which will be the ES Logging Cluster (#2 in your list). Initially, when you install ECE on your first host, that is where these clusters will be added as well, but as they are clusters, their nodes can technically be moved.
Re: 2: ECE uses Elasticsearch to keep track of cluster metadata. We basically use our own product as part of the ECE admin console. (We have to store information about these clusters somewhere, so what better place than our own product?)
Re: 3: The logging cluster will be used to collect metrics on all clusters running in your ECE installation. There will be more information on this in the beta1 documentation, but it is not available yet. (I own the documentation for ECE.)
I hope this helps,