I wrote a blog article about ways to search symbols:

If you're doing overland mapping, there are generally symbols available for marking spots on the map in the :CC2BO: category.

When picking file type in the save as dialog, use any of the "rectangular export" ones, they will prompt you to define the rectangle of the export after hitting save.

Have you considered using a different style of roads? Those dashed lines works on overland maps because they're only representative of the feature, but on close-up maps like these, they come out looking a bit out of place. Maybe a dirt brown fill with a small edge fade instead?

Most scale bars are 100, but there are exceptions like the style from that thread, where it is 200. Some styles also have multiple lengths, like the Schley overland style which as two at 100 and one at 200

The easiest way to check the scale of it in any style is simply to place it (Make sure the current symbol scale is 1) and measure it using the Info->Distance tool.

Digging a bit, I found that transparency only works for images if they are set to use alpha transparency in CC3+.

Use the :CC2EDIT: on the image, and switch it to alpha transparency, and it should work fine. (remember to thaw that frozen layer first, otherwise you can't edit it)