I did not read the whole thread, but auto enabled opt in to track IP and/or URL is a very very big no-go for Europe’s data protection laws and even bigger deal if you wish to have any relationship to the enterprise segment here.
Perspective: Google analytics in Germany is only allowed to provide the first three segments of an IP adress. Even if you have a mile of legal documents attached to the page. Don’t underestimate the huge sensitivity for data protection outside of the US.
If you wish to track, make it opt in on first run with appropriate data protection disclaimers / non-nagging.