Google Event Tracking on Slides

Yes, you could do this using a custom slideshow template, maybe add a metabox for the event code using Advanced Custom Fields, and then load that script with the custom slideshow template.

I use a handy plugin called Simple URLs, which you can use nice short links to anything, like a long affiliate URL or a PayPal link, and it tracks the clicks on those short links, so you know how many times they have been used.