First of all, nice work!
The optimization for GP4 is going well and you are improving your skill every day.
Now, to answer you:
1-As I said, textures names into material editor must be the same than the texture: So if your texture name is dtm_mercedes_02.tga, into material editor, the texture name must be dtm_mercedes_02.tga, only. But I guess this is what you did, as it loads correctly in game.
Don't worry about the chrome.bmp light texture. It loads automatically when you open .gp4 file into ZM1. You don't have to care about it...
Advanced work: Better would be to give short names to your textures (no more than 8 caracters) for the lower lods work and to group some textures to reduce their numbers. But this is another step. You will see later, if you wish...
2-You don't have to set glowing mode for the transparent objects: the object z_cockpit_visor do it automatically. What you can do, eventually, is to modify the color of the "glass" texture from your cars.wad to change the opacity. Z_cockpit_visor is related to the glass texture by default in game.
The problem is that the windows are textured with textures names or numbers, so if the windows are transparent, the names and numbers will be also transparent. There are some ways to fix it but it needs some work and time consuming (to create faces behind the windows, to attach them with the cockpit object and to map these faces with the windows texture , only with the part you want to see in game).
But I haven't got the time to explain you, right now.
Better is either to set the rear windows non transparent (I know that the result could be strange), or either to set the color of the glass texture from your cars.wad to grey for more opacity of the windows in game... It is also possible to play with the glowing mode for the opacity but this is an advanced feature a bit difficult to do because of GP4 specific objects.
Just try and test with the glass texture, first... In any case, the names on the windows won't appear completely by modifiying th opacity, unless you create faces mapped with another object than the z_cockpit_visor object.
3- It seems that some textures are not well assigned to the car (Suspensions, body driver, driver seat, exhausts). Check the names into material editor and textures. It looks correct into ZM but my guess that material editor names and textures names are not the same...
4- About the break lights, I have only had to use one until present, for the F1. But the break lights will be only enabled into intermediate or wet weather conditions from what I know. Maybe there is a way to use them all the time but I don't know. BTW, you have to use the rear lights not enabled on the cockpit object and make a copy with the light enabled as the rear_light_on object.
Maybe you could have a look to others mods for GP4 with DTM cars or others cars to see how the rear lights are working... Just an idea...
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