You can typically find fill pencils like minwax that will fill the nail holes and match stain color.
Sorry for the delay for the response. The molding is 3/16" at the "top" (perpendicular to the 3/4" face) of the curve and is 1/4" at the "bottom" of the curve (perpendicular to the 1/2" face), see photo.
Yes we have a retread stair nose available special order through your Home Depot. Let us know if you have any other questions. Thank you Stairtek Customer Service.
No, this is not bendable.