A) right click on a textured face (not on a textured group/component) and select in the context menu that appears: Texture > Position > see the tiled texture that you can now manipulate with the four grid points. Each grid point has a different meaning. One is to rotate and/or scale the texture.
You can also, without doing anything yet, right click again to start ending the manipulation and select ‘rotate 90 degrees’ > Done.
B) you can create your own textures or import them as jpg and create your own library.
C) See B), yes you can import hatches as texture. Create them in an image editor if you wish. There are some neat hatches collections available already.