Sorry about your job. Hope this situation normalizes soon so people can get back to their jobs, or at least have an easier time finding a new one when not everyone is trying to hunt in the same limited pool.

At least the time isn't wasted when you spend it mapping :)

Kind of. You could do the same with a solid color and the transparency effect.

Transparency in images is a common thing though, and is used in a lot of the CC3+ symbols. The advantage to have it baked into the image instead of using an effect is that you can control the transparency for each pixel of the image, while the transparency effect applies equal to the entire sheet.

These tools use a raster image for their fill, which is just a 1-pixel image with either a black and white pixel. This image is set up with built-in transparency. You'll find these fills in the fills list as Solid 10, Solid 20, ... Solid 90 and Solid White 10, ... Solid White 90, where the number indicates the opacity (10 is almost fully transparent, 90 is almost fully opaque).

When overlaid other elements in the map, the pixels below are mixed with that fill according to the transparency level of the fill, thereby serving to lighten or darken whatever they overlay.

Looks good. The main thing that seems to be missing are effects. Especially the piers look very flat on the water without some kind of shadows and/or glows or bevels to help elevate them a bit.

Well, as the Tome itself states in the introduction, it is written for intermediate to advanced users. It does assume some knowledge of the basics of cc3+, and relies on the user having worked through the tutorials in the manual first, and probably worked a bit on their own before diving into the Tome.

Also understand that the tutorial is written for that particular map in mind, it is extremely difficult to figure out all the ways a user may want to do things differente from the tutorial and reference those, that would also make the tutorial extremely bloated. The goal of the tutorial is to teach the user various techniques based on the requirements for that map.