1) There is no need for a negative rating. If you didn't like my recommendation, all you have to do is continue to ask questions. I am giving you the best, XXXXX XXXXX most cost effective option by using Wiremold for your application.
1A) Refer to my response shown below for the typical issues in attempting to install wire within existing cinder block voids.
2) As I mentioned in my previous post, fishing a cinder block wall is very difficult since all of the vertical voids need to be free and clear and line up. It becomes a matter of luck if the voids are not obstructed since you have no idea as to what is on the inside. The only way to determine if the vertical voids are clear is knock a small hole in either the left or right hand side of the cinder block and use a fish tape to go up or down. Even if you are successful to fish a few blocks, you could wind up with obstructions in the next vertical block. The middle portion of cinder block cannot be fished since this is all concrete. If attempting to do this, you could wind up with numerous holes that will need to be re-patched with mortar and re-painted.
Also, installing wall boxes within the cinder block becomes an issue. In order to make a clean cutout for the wall boxes, you would need a carbide tip saw or a Dremel tool with plenty of spare grinding wheels. If using a chisel to make an opening for a wall box, there's always a good chance that you will chisel away more concrete that is needed which in turn now presents a problem to secure the wall boxes.
If attempting to install cabling in a horizontal run within a cinder block wall, it simply can't be done and is impossible since the voids only run vertically and not horizontally.
3) Wiremold is widely used and specifically manufactured for applications such as yours. Next time you are inside an older building constructed of cinder block walls, take a look around and you will find Wiremolding widely used in retrofit applications that are identical to yours.
4) The following link provides comments from other electricians if running electrical wiring in an existing cinder block wall: