Hey Knox,
I agree that this would be awesome. Marketo doesn't have this capability right out of the box. You can find the Leads who have clicked a link more than 25 times, or opened an email 25 times, or visited a webpage 25 times, but you can't find someone who has 75 total interactions. You could create a smart list using the filters I just mentioned, but if someone clicked a link 20 times, but visited a web page 40 times, as well as clicking 25 links, they wouldn't show because they didn't qualify for the clicked links portion. That make sense?
What you could do is create a new scoring system. Every time they do a certain behavior, add one to their "Interaction Score." Then, you could build reports off of that. You could filter their activity log to see how they got that score. This approach could take a while to build, but may be what you are looking for.
As far as the Opp Analyzer goes, I am pretty sure (need to double check) that only actions that are successes or created an interesting moment will show. Just something to consider as you move forward.