I'm curious if these people properties can be used on the segmentation screen?

We're were doing something similar with mixpanel, except (in mixpanel client-side parlance this is called super properties) we have to send all attributes such as "number of pages viewed", "amount of money paid" with all our events in order to segment by that data.

And sending emails based on analytics is incredible! I've always wanted to build that for my app but didn't have the resources to. Is it horrible to gloss over the privacy concerns?