Limit Override wont disable the limits, it will still stop if a limit is hit, you then have to press the reset button and you can then again jog. As you have said it is possible to jog the wrong way. I can see why you would want to make this foolproof but maybe that is what is wrong with the world nowadays, people try to make things as safe as possible so that no harm can come to people or things and that makes people not think about their actions which in turn leads to more danger when things dont work as expected
Softlimits are exactly what you are looking for, they will stop the axis moving beyond the soft limit in either direction. To set them up depends on where you have your home switches positioned, if you have them so that the tool is lower left corner of the table (looking from above) and the tool is furthest away from the table in the Z axis then X and Y Min and Z Max is set to zero, then X Max, Y Max and Z Min are set to each axis travel. The Z will be a negative number but X and Y will be positive.
If you have your home switches at any other positions then you will have to set a home off value dependant on their position.
Hood