Should I Be Using Events or Variables?

I am just starting out with Piwik. So far I am loving it, I have a goal setup for when people fill out demo forms, etc.

The only issue I have right now is the following. The main statistic I need to track is a landing page, with a referral id.

I setup the page to create a custom varriable that logs the referral ID. I also have three things a user can do on that page that I would love to track - one is when they upload a file, use the contact form or view a media file.

Would events be proper for this? I need them all to be basically namespaced to this “referral id.” I want to be able to email the referee’s statistics about their pages - how many views, files uploaded, contact forms filled out, media watched, etc.

when they upload a file, use the contact form or view a media file.
Would events be proper for this?

Sure events are designed for tracking this kind of things

Also Events store custom variables so you can have both at once.

The only thing about Events though, is when I use the API to generate / display / email a custom report, I want just the events that happened under that unique referral id. With that, would it make sense to keep using Events and just, some how, parse and build the report that way?

I want just the events that happened under that unique referral id.
for this you can use Segments: http://piwik.org/docs/segmentation/ to segment only for this referral id