Can I do simple scratching with traktor dj 2 and a midi controller?
Not with any old MIDI controller @Stax67
https://www.native-instruments.com/en/products/traktor/dj-software/traktor-dj-2/compare/ shows no MIDI I/O or Mapping capabilities, and a handful of compatible devices.
If you have a supported controller it will probably be fine.
But keep in mind that Traktor DJ 2 is not updated any more. Any specific reasons you want to use that software?
@Michael Niotakis thanks.
@lord-carlos thanks, I'm looking to get a simple set up for trying to scratch some samples over some beats (without having to have a turntable and mixer). As I use some NI plugins, Traktor jump to mind (I actually thought a cut down version came with Komplete, but it doesn't) and I saw a free version. Someone has recommended Mixxx as an alternative.
Probably IOS Rekordbox + FLX4 would be your best alternative. IMO