Hey mate.
Firstly I’d have to agree with Stiffy on the bump, 20mins is a pretty short time to get a reply, even on one of the largest DJ forums around, of which DDJT is most certainly not. Patience will reward you.
As far as the mapping goes, yes, the crossfader and jogs work fine in TP2. The stock mapping there works a little differently to the VDJ mapping, however if you’re willing to fiddle around you can get it working the same (as I did).
I can’t comment on the 4-MX, but I have owned the Mixtrack Pro and I can say it’s a quality unit, you really can to wrong. If you’re unsure, read reviews on both, and go to your local store and try them out. Most of the time it’s up to personal preferance.