1. I typically use SQL: "HANA_Resources_CPUAndMemory_History" (SAP Note 1969700) which is also based on HOST_RESOURCE_UTILIZATION_STATISTICS and so far has provided me with reasonable, consistent CPU information. Can you check if it also works for you? Be aware that you can adjust the "Modification section" of this command, e.g. if you want to have a different aggregation or time granularity.
2. The load graph / nameserver history is a kind of left-over from TREX times while the other histories are developed for SAP HANA.