I have read the Manual and Bob Smith's setup guide but couldn't find an explanation for the teal green vertical lines in the suspension diagram that go with the setup page. My guess is that it is the direction the contact patch will move as it deflects up (that is, the perpendicular to the roll center).

As an engineer I enjoy all the data that LFS displays both in the setups and in the Force view. However, would it be possible to add the vertical spring rate of the tires to the information shown? The tire spring rate becomes quite significant with modern race cars and their super stiff suspension systems.

I think that the green lines show the force that is applied to the tyre.

You are correct about the teal lines.

You can get the tyre vertical spring rate from the car data output files but not live while in game.