Clay, wouldn't it be simple enough to add google analytics to the page where the signup form is located? People who signup and then see your "thanks for signing up" page are marked as a completed goal in GA. That's how I track signups.
Once on the list, Drip helps me track engagement as people click various links.
Oh wait, Drip's not on your list.
Drip can do both of these things.
Is there a reason Drip isn't on your shortlist?
Rob Sobers has this excellent example of using Drip to automate sending Net Promoter Score surveys to customers. No, you didn't mention you were looking for NPS surveys, but Rob's article shows you how you can use Drip trigger links and automation rules to do what you're looking to do.
Also, Drip has added a really powerful workflow engine that makes if/then logic a breeze. Here's how to build workflows like this in Drip. Drip also gives you these already-built blueprints for automation, customer tagging, and using if/then logic based on customer engagement.
Brennan Dunn has a course on how to use Drip to do precisely the kinds of polling, tagging, scoring, and segmentation you're describing. There's a great demo video on his landing page there showing you a little bit about some of the internals of how you might use Drip automation to accomplish what you're looking for.
Lastly, Drip has this free, 11-video course, as well, to help you get started.
Just an alternative to the products you mentioned.
Hope this helps!
As an aside, I apologize for the link armaggedon in this reply. I use Drip for my business, and while it may or may not be right for you, I think it's worth a look. These are not affiliate links, just trying to be helpful.