Setting base ignition timing pre start up

Hi,

I tried to ask this question once but it disappeared into the cyberspace once i hit submit. I have 4 questions related to this module.

1. There is something related to the position and markings on the crank pulley and the tdc of the ignition? Like when a number on it is pointing upwards is that the angle at which the spark occurs? A guy also told me the number of tdc you set on the vedio here can be between 10-20° But not more than that.

2. What is the use of the number that is displayed on the lcd screen of the timing light? We ignore it? During the crank test ofcourse, because you put ten in the laptop and the light showed 2 at the far right.

3. In an EFI car, does the pressing of Up/down buttons in the timing light set any drifts or adjustments? Without even accesing the ignition table? Or at all? Or is it just a useless button that makes no sense.

4. What's engine speed reference offset in your video? A friend of mine sent me a screen shot from his vipec where there is "Adjust offset until ignition matches th number above" and its set at -82 degrees, he runs an rb20det.

Sorry going to start the car for the first time so a bit nervous.

Thanks.