Unfortunately I haven't used this or know what this is as it's pointing to your localhost.
When you say Hyperic API, are you referring to the out of the box HQAPI commands that use hqapi.sh or hqapi.bat?
If so, then
1. per connected server (resource) what are the measurements configured - yes
2. what are their threshold settings - yes
3. what are the actual values of the measurements with timestamp of the last measurement. - i've never gotten metrics from this, but the metricdata command may be what you're looking for
If not, then just some general observations when working with Hyperic.
From my experience, when you query for a resource, you'll only get metrics for that resource. So if you provide a resource id of just the server itself, you'll only get stuff like cpu and memory because those measurements belong to that resource.
Each server can have multiple resources so in order to extract information for those resources, a separate resource id that was created for it should be used.
Ex. serverabcd = resource id 1234 = measurements cpu, memory
/ mount ON serverabcd = resource id 12389 = measurements free space, space used, etc.