I done have a "set home x and y", I never used them, so didnt include them, there is room to add them if you wish. I just use the Zero x and Zero y, I have home/Tool change position switches on my machine.
The Front to Rear tool post DRO, is if your lathe has a front and Rear Tool post, it is for you to set their seperation distance, and then you have a button to choose which one to use.
The Tool number setting buttons are for you to pick i.e. Tool 1, and then you can touch off the x and then the z offsets, this loads those into the tool table for you, there is a button to manually edit the tool table as well.
Scott