Glad you found the tutorial and plugins useful - dismantling existing code is definately a good way to get a handle on a new language/environment.
You can get pet names from the API but as you already considered, they may not be unique. AFAIK traps and other aoe effects will just list their name so they will look the same no matter who placed them.
Skirmish soldier kills will be a bit tough as there is no way to automatically get the soldier names. And many people dont bother naming their skirmish soldiers so you'll likely have multiple generic names.
You might also want to strip off the leading "the " from generic mobs before tracking the count.
Have you considered storing the kill count at the Server level so that you can compare your own characters as well as seeing totals? Storing at the Account level would be nice, but there is no way to automatically distinguish two characters with the same name on different servers
