Hi Marcel, the first thing you need to do is upgrade Grbl to a newer version.
In the later versions of T2Laser you will find either 1.1c or 1.1e which were compiled with my settings. You can modify the steps/mm to your machine and enable/disable laser mode via $32 if needed.
It has homing for X and Y axis enabled on D9, but not Z so if you want to home Z you would need to compile your own firmware. You set the order of homing and the pin assignments in the Grbl code and then compile the hex.
I home X, then Y and ignore Z since most machines don't have one. If you separate the home/limit pins then you can home both axis simultaneously but that's more wiring so single pin works fine for me and I think as a group here we decided it was the way to go for simplicity.
Oh, and yes. Homing is great! It should be included with these machines.
(on my CO2 which does have a Z-axis for focusing I do not have any home switch, it's just manual up/down which is why I added Z-axis controls in T2Laser but have not implemented actual homing - the home button just returns to a home point)