It sure sounds like a challenge! However, and I do apologize, but we don't have any experience with custom-built applications like this, and as such we can't really help you here. Best of luck!
We have not tested the dockStubz with the Numark unit ourselves, but we've had other customers ask us this before. None of them wrote back to confirm if it worked, but we haven't had any reports of issues either. Our return policy is 60-days from your original date of purchase, so you're welcome to give it a try and return it if it doesn't work for you.
Yes, our dockBoss+ cable provides the audio connection, plus a micro USB connection for charging.
Yup! It's compatible with all iPad, iPod, and iPhone models, except the Shuffle.
Sounds like you received a defective cable. Please contact us at service(at)cablejive(dot)com so we can get a replacement to you.