
. OK, let's take it one by one.
1/ objects numbering starts from 0, not 1. (AC_START_0, AC_PIT_0, ...). This is important.
AC_HOTLAP_0 is probably not mandatory to run basic track, but in the end it's just a matter of copy/paste.
2/ there are many *.ini files you can customize under \yourtrack\data folder. These will influence the looks or the behavior of your track.
surfaces.ini
Copy one block of instructions and customize it to fit your needs.
Start with index 0 - like [surface_0], then [surface_1] and so on
Key - this is the name you'll have to use for your mesh. Pay attention to it, cause sometimes the AC engine will get confused if it looks like something else

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crew.ini
Sets the position of your pit dude
Parameters: to left (1) or right (-1)
groove.ini
The groove is used to actually give the track some "life", being dynamic with the advancement of the race. However, if you would like to affect the way it behaves, you can do so by adjusting the parameters inside the groove.ini.
Parameters: There is a min value, a max value, and a stepping. Play with these and I'm sure you'll get what you are looking for. I would suggest not to cancel it all together, but maybe just to start with a higher min value

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3/ you can happily modify the FBX inside SDK editor, no matter what texture you have set inside 3d program. You can reassign all of them here.
4/ texture folder must always be named "texture", not something else, if you want the SDK editor to use it automatically. Otherwise, you'll need to reassign all textures manually. Also, don't forget to "save persistence" after you make changes.
5/ name of the folder MUST be identical to name of the track (also do NOT use capital letters)
6/ scale => meters.
Have fun

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