No. You need to only enter the length and the height of the wall - everything else is smartly calculated by the generator for the best fit.

Yes. The walls get generated along with their UV maps and a default material. You can easily apply a different texture of your choice for this material, or use another material instead.

Yes. You need to create multiple materials with different textures and assign them to the corresponding walls from the materials tab. Each wall also has got its own UV maps, so things will be easy to handle. We are here to help you for any specific customization.

Change the scale factor in the mapping node for Wall-Brick-Material. Based on the size of your wall, you need to use a suitable scale factor for its texture. Please check the documentation for complete details.

You need to change the value of the Weather Seed. Experiment with this value to create variations in the weathering pattern. To change the amount of this weathering effect, use the field called Weather Factor.

It is the intended behavior. The highest permissible horizontal gap depends on the brick size. The system will use the highest possible value if you enter anything beyond that.

Reduce the displacement value. With higher displacements, the system fails to calculate the UV map correctly, it needs manual adjustments in some places. So the bricks in those positions won't get the texture. The problem is lesser in the Advanced version, but it is still not flawless. Displacement jeopardizes the UV map.

As you increase the wall dimensions, the underlying calculations increase heavily. So it is only natural to take more time depending upon your system capabilities. If you have limited resources, you can create a part of the wall that you need and then use instances to repeat it many times. It will be faster and accurate as well.