On a hard drive, where is the physical location of the first sector. Is it towards the center along the axis of rotation or along the outer edge? Does this vary from manufacturer to manufacture.
It is located at the outermost part (edge) of the platter (or one of the platters, if the drive has more of them). AFAIK, it's the same for all manufacturers.
Since data is written to the outer tracks of a drive first, hence the drive is filled with data from the outside in. The fastest data transfer occurs when the drive is first used and data retained in the outer tracks.