Hey,
I'm running sometimes Cross 3 on my MacBook Air 11" (mid 2013) and it works fine, also Video Feature works but if you run too much at the same time the Video feature is sometimes freezing.
I'm also running Pioneer CDJ 2000 nexus models in HID (sound card is an DJM 900 nexus) on that MacBook and it works fine. So if you only want to run Audio on that system it works fine for me.
But you need a good USB hub to connect all the devices

AND I prefer you the bigger version because of the Screen is a bit to small if you run all in full details. I only run the GUI at Browser in Fullsize (all other informations are shown at the Pios). For Video the Screensize of the 11" version it too small to work good with it.
I hope it helps you!
regards
Christian