Okay, so my general feelings about this class were rather positive when I first read the fluff concept. It's a neat idea worth exploring.
The Dual Identity seems fun and I enjoyed the camaraderie it brought to the table.
But the fact is, as much as I like this class, it is crazy broken and needs serious changes.
My Warlock is not much of a spellcaster, he's not much of a fighter, and sadly during combat, I am hampered by an extra aggravating mechanic where I need to find an out of the way place to hide so I can spend, essentially a full minute of combat to transform into my spooky faced bad ass persona.
This borders on moronic at times and it saps the fun out of my character as I am forced to find the thinnest excuse possible to hold up the central conceit of my character. Furthermore, there are very few real reasons to SWITCH identity since it seems the only serious ramifications for a switch are a change in alignment. During play I killed two enemies as my social persona and had a series of terrible rolls in my vigilante persona. This lead to a series of hilarious, but rather telling jokes about how my "Secret Identity" was less useful than my normal persona.
SO in practice, the Dual Identity thing is fun but it's effing goofy and it needs to be fixed. And the crazy thing is? I LIKE this aspect of the character, I like the dual identities, because otherwise you seem to just have a bunch of other classes with no defining purpose.