1. As Joe stated, all you need to do is change the base to ControlBoard in the Component.txt.
2. You can set the base to Chassis but it will cause an error if you try to attach it like a normal component. It also doesn't appear to have any effect on the armor types.
3. You can add more armor types but you can't add new textures. The format for the Armour Definitions file is:
MaterialName
Description
Texture
ArmorID WeightValue PunctureValue HeatValue ConcussionValue
To my knowledge, the Texture line doesn't do anything but be sure to use an ArmorID between 0 and 3 (inclusive). The EXE looks at the ID and uses an associated texture file (0:plastic, 1:aluminum, 2:steel, 3:titanium). The weight and concussion (becomes the chassis HP) values are the only ones that appear to be used (after being multiplied with the surface area). The puncture and heat values seem to be unused ATM but the EXE refers to them as those names.