I thnk the cdj 400 can be used as midi controllers! So deck A and B controlld by the Cd decks, then just route the audio out of your interface to the channels on the xone 32.
Personally i’d never go back to Serato. It’s cool, and if there was a party and someone had it, i may just bring a usb stick and play on it but for a home set up vci-100 is perfect.
Just out of interest why would you want to go more analogue? Its more limiting no?