Hi yrbender, until you have a more experienced understanding of how all the electronic terrain assistance works, just set the terrain response to the setting that best suits your needs and let the LR3 do it’s own thing.
While diesel powered 4x4s are normally better for off road use, some of the settings on the LR3 actually vary the response of the accelerator pedal on the petrol versions of the LR3s to assist in the control of the LR3 while off road and you need to get use to these sorts of features to be able to get the best performance while off road.
The one feature that you should learn how to use as a first requirement is how to use the variable speed controls while in hill decent.
Easiest way to do this is to find a nice steep road in your area and practice going down it while using your cruise controls to vary the speed. This can make a huge difference to your off road down hill runs, up hill driving is pretty well looked after automatically by the LR3, as you would have probably already discovered.