Great work!
I'd be happy to go through the Java code and redirect all the sysout and printStackTrace() references through a central function that can log out to OpenLog or just print to console, based on xsp.property setting if you wish. it shouldn't take long to do. I could either add the XPages OpenLog Logger classes to the template or point it to the OSGi plugin, whichever you prefer.
With a custom error page, any uncaught errors not yet identified would also get logged (I find that very useful during development).
If you're using source control (although I know it's not necessarily foolproof for all traditional Notes functionality), I can also set up a repository and project on OpenNTF Stash for you.