Questions about some features we need

1: I don't understand your question completely. It is possible to program various keyboard keys and MIDI devices to be trigger surfaces. I'm working on a profile for the Novation Launchpad controller, which could theoretically place up to 64 instant recalls of whatever you want. If you were to assign scenes, cycles or switches to a hotkey, I think that would to what you're after. Even so, if not, once you're familiar with the software, it gets fairly easy to use. The training curve is somewhat high and it might not be good to surprise a DJ with if they aren't familiar with it. I'm not saying they can't learn it, it's just something you don't want to impose upon someone not familiar with.

2: If you have certain songs, you can place them in a timeline using Compu Show's EasyShow module and then design a custom show for those songs. With markers, you can dump multiple songs into one timeline, but at the same time, you can just load and unload songs as desired. It will pull in the audio as well. As far as push of a button? Sure, no problem, push the space bar. Just have your first scene use a fade and you'll transition nice into it.

You can run scenes, switches and cycles in Compu Show directly while loading up a show in Easy Show.