Overall, this is a great showcase for your voice. I'd avoid using pre-established content, though- it's nice to know you CAN do imitations, but unless someone is looking for that specific voice or style of voice, they usually get glanced over. If you like a voice, try imitating it, then making it your own. I forget which voice over actor it was- but they said all of the characters they've ever created were bad imitations of someone else. Like when Seth MacFarlane (bad example, I know) was creating the voice for Stewie, he took a character from one of his favorite musicals (Professor Henry Higgins from My Fair Lady) and gave it his own spin.

A lot of these skits sound somewhat similar, however. You've got a unique voice, no denying it, but try to interlace character voices with situation voices. Something you do a lot better than I do, however, is add emotion into your work. This was a joy to listen to, start to finish, because it sounded like you actually *cared* about what you're doing. If you don't care, then why should the listener? That's something I always struggle with.

At any rate, good job, and I hope to hear you in other work!