Collection of misc modding information, as I stumble uppon. Hope it can serve as a starting point. Happy modding 
Q: Can digital gauges be used ?
A: Yes, digital gauges are supported
Q: Can animated textures be used ?
A: No, animated textures not supported.
Q: Are there any free assets available ?
A: No, not from Kunos official.
Q: Will the user created content be protected against ripping ?
A: Kunos: We'll try to protect contents. Obviously we can't spend all development time here...
Q: What is the maximum vertices a single object can have?
A: The only limit is the number of coordinates that a mesh can have, 65536. Coordinates are vertices, normals, UVs and more. There's no way to check this before exporting, but the editor will warn you, when importing, if an object exceeds that number (the object will not be imported), giving you the possibility to divide it into more objects.
Q: Can digital gauges be used ?
A: Yes, digital gauges are supported
Q: Can animated textures be used ?
A: No, animated textures not supported.
Q: Are there any free assets available ?
A: No, not from Kunos official.
Q: Will the user created content be protected against ripping ?
A: Kunos: We'll try to protect contents. Obviously we can't spend all development time here...
Q: What is the maximum vertices a single object can have?
A: The only limit is the number of coordinates that a mesh can have, 65536. Coordinates are vertices, normals, UVs and more. There's no way to check this before exporting, but the editor will warn you, when importing, if an object exceeds that number (the object will not be imported), giving you the possibility to divide it into more objects.
