Hi,
you can get a list of all registered users by installing our premium add-on User Overview:
https://slimstat.getused.to.it/addons/wp-slimstat-user-overview/
When you click on a particular user, you will get all his/her activity on your site, including what CPT’s s/he visited. WP SlimStat comes with a quite powerful filtering system that allows you to drill down your reports and get exactly what you need. The report however will say ‘cpt:product’ and then the URL or Page Title of your product (configurable in the settings).
Stats are stored for 4 months by default, but you can change this timeframe in the settings. It all depends on how much disk space you have. 10,000 pageviews take about 1.5 MB of disk space.
As for your final question: no need to query the database, filters give you all the power you need right in your WP admin ?? And you can also export your data into an Excel file (requires premium add-on).
But yes, if you need to dig deeper, then you can take a look at the database schema and perform all the queries you want.
Best,
Camu