I have been tasked with writing entries to the Windows security log. The entire project is Win32 C++ code. I have already written (with help from various online resources) a logging class that handles registration, deregistration, and code for executing the ReportEvent() call. Also, I've done the mc.exe and rc.exe steps for my event logging, if that helps establish where I'm at in the project.
My question is a multi-parter:
For the moment, I'll just deal with the first question, because the answer to that probably renders the rest irrelevant.
Only Local Security Authority (lsass.exe) can write to the security log. This isn't a matter that something else attempting to get the privilege will fail -- it's a matter of there not being a way for anything else to even request the privilege at all (and this is by design).
From there, about the only answer to your other questions is "Sorry!"