Reply to iPad djing - article related.

I have been looking for a while into(portability is the main thing) this but i there are many things not clear to me. I have noticed one trend on this community , that most of the people here use iPad along with laptop. While this sounds good, i want to eliminate laptop completely. Here are my questions. I will answer my questions but correct me if im wrong.Thank you for helping me to understand it better

1. Can you hook up an external soundcard somehow? If so, would DJ apps recognize it?
My answer: No you cant or you cant but dj aps wont work with it.

2. Which DJ app is the most useful? All I want this app to do is to SYNC, have a CUE and somehow being able to split the ipad soundcard so I can cue tracks in headphones or have an external sound card connected. Also it should have pitch bend to do corrections.
Also it would be nice to have this app
My answer: I dont know

3. Is there any app + audio card for iPad that can do all of the following in #2 but to mix it in external mixer?

Thanks!