Just to confirm Demort's comments on suspension set up, as an owner of a 2014 Platinum Edition, may be slightly different on the early models (or even later ones!)
All of them will have the left lever which is the 4 wheel drive 'control' I think its exact function varies accordingly to model, in that we have the 3l Diesel and we don't have the diff locks, but other models do. Think on ours we've permanent 60/40 split, and the offload mode alters what PSM does.
Middle lever is PASM, and that can be fitted with steel or air, think they all have Sport, Normal & Comfort. Think the handbook says Normal for road, sport for the obviously stiffer throw it about set up, and Comfort is off road. Ours runs in Normal most times, and pop it in Sport if I'm pushing it a bit or its very twisty, does firm everything up.
Air has a number of heights. Lowest is loading, then low setting (ours is usually in this mode as it looks better), normal setting, then 2 higher settings which are for off road and (I guess) tougher off road respectively.
Air also takes road speed into account, so it won't allow these higher off road settings above certain speeds, and moves you to normal. It automatically moves you from normal to lower height if you go over about 85mph for around 10 secs or longer, and moves you back as you drop below about 50mph - but it stays in lower if you have actually selected that height. It also goes to lower as soon as you hit 100mph. There is also a further even lower setting between lower and loading which is not user selectable, but is automatically selected if you go over 130mph for about 40secs. Lastly you cannot drive in loading - if you accidentally move off its supposed to raise itself up straight away to avoid damage - never tested that for obvious reasons.
Not got PDDC so no knowledge of it.
Hope this helps.