1) Am I correct in thinking that kiwi will give me granular control over which events go to Orion?
Yes and that's definitely the right idea. Unfortunately, the Windows Event Log Forwarder currently only works with Orion Syslog Server. We're working on another release of Windows Event Log Forwarder that will work with Kiwi Syslog Server as well.
In the interim, I think your best bet is to check out the APM Windows Event Log script which can be found here: Windows Event Log Count-- updated on Sept 9, 2008 (SolarWinds)
2) Is there currently any integration between the two products that can help me do this now?
3) What is the roadmap for full integration with Kiwi and what will be some of the high level features that will be added to NPM? Will it tie into APM?
We're still working through that roadmap, but the intent is to integrate Kiwi Syslog Server as a replacement for Orion Syslog. This may take some time since we'll need to think through how we migrate your existing rules and filters from Orion Syslog to Kiwi Syslog.