SMF70NRM and the other fields are described in the SMF manual -- whether or not they are accessible from RMF, I have no idea since we don't run RMF here. If you're limiting yourself to the tools you have familiarity with, you may not get a very good understanding of the data. I usually look at the raw SMF data first before attempting any analysis to ensure I understand the limitations of the data.
The z/OS 2.1
RMF User's Guide manual has a section on RMF Spreadsheet Reporter that describes the Workload Activity Trend Report, Excel macro RMFR9WLM, as (emphasis added by me)
This macro provides performance reports and analyzes your system's behavior. It also supports zAAP and zIIP workload analysis and workload projection.
So you need to find out what needs to be done AT YOUR SITE to enable zIIP analysis since it is already available to you. This is something that we cannot help you with since we don't work at your site and do not know how to gather the data you need. Contact your site support group.