Even i am doing the exct same thing, with the 2 limit switches on the min and the max end of the axis, and the home somewhere in the middle. Even i am using the Work offset option.

The only problem i am having is that when i click the "Ref all home" button, sometimes the tool is at the negative side of the home switch and it keeps going negative until it hits the limit switch and the machine shuts down. Now i have no way of telling the machine which side of the home switch the tool is.

so any views?