Traffic lights - help with paths and other things

Hello,

Couple of questions regarding traffic lights.

1. What /how much/ paths are necessary for effective traffic light? Should I only select those near the lights (stopping point) or all that are 'part' of intersection? Also, do cars stop at the start or at the end of a path segment?

2. Pedestrians, how to setup paths for them. I tried something and my issue is that they block traffic because cars want to give them priority even though it's green for them, but yet the people won't cross because it's red for them

3. In general, can someone attach screenshot of phases so I can use it as a reference.

Thank you very much!

Thank you for answers and the screenshot is very helpful.
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Another question, is it possible to remove paths that I already attached to the traffic light?

Edit: for now I simply remove the path segment and create new one.