Moving them is pretty easy:

For the stuff under 'Documents' ==> move it as you please. CC3+ doesn't reference this stuff (unless you yourself have told it to do so by manually putting images in here, and then putting these in your maps, if you have done that, you also need to update any maps referencing stuff here)

c:\ProgramData\ProFantasy\CC3Plus ==> This is the main CC3+ data directory. You can move this as you please, but you need to update the file c:\Program Files\ProFantasy\CC3Plus\@.ini with the new location. [This is a normal text file, can be edited with notepad, but you need administrator permissions to do so since it is inside the program files hierarchy.].

The only things that can go wrong here is that if you have manually added content to this folder [This IS where all map resources should go, so adding things is fine] and used it in your maps without using the @-identifier in the path. This should not be an issue with standard content, only custom content that was improperly used. If this is the case, maps using fixed paths needs to be updated, and the easiest is to open them in CC3+, and then type FFIX on the command line as this changes full paths to relative paths. But this has to be done BEFORE the move. You can read more about relative paths here.

Lastly, the {1CE7E770-44A2-4D72-991C-3E7870515B1C} folders you identified in ProgramData ==> These are not used by CC3+ itself, but by the windows installer when installing/updating/repairing/uninstalling CC3+. For normal operation, it is generally safe to remove these if you need the space, but keep them somewhere you can copy them back when windows complains about missing installers if you try any of the above operations.

Note that putting things on an external hard drive will probably slow down CC3+ a bit. It can't keep everything in memory, so it need to access those image files regularly whenever you scroll/change zoom/issue a redraw. External drives are usually significantly slower than the internal one. Personally, I recommend keeping the data directory on the internal drive for the added performance, but feel free to experiment, after all, it can easily be moved back.

Grids are just entities, you can use change properties on them and make them as wide as you like (They're usually on a frozen layer, so thaw it before attempting to manipulate the grid). Other things that also usually work very nicely is to add a small glow effect to the grid.

The default line in CC3+ is a line that is as thin as possible (which usually translates to a single pixel). This works fine on screen, but can lead to nearly invisible lines on prints/exports.

Not sure why it turned out differently, but both are minor scale issues that are easy to change.

For the roads, click the Line style (LS) indicator in the top statusbar, pick the Roads entry and hit edit, then set the pattern length lower, for example to 1.

For the fill, click the Fill Style (FS) indicator in the status bar, go to the bitmap files tab, select Farmland_MS from the dropdown, and increase the width and height values for scaled. Try doubling them from whatever you currently have as a first step:

Nicely done . I love this style. Looks a bit light in the vegetation department though. Maybe some trees to show major forests.

No. That is only required when adding additional resources to the program. But this is a map bundle, and you can keep your map files wherever you want.

Note that the bundle do contain maps in many different styles, not all of which you will have access to with just the basic program, so you will see red X's when opening these .fcw files in CC3+, but that isn't an installation issue, just that it was made with resources you don't have. For these maps, the bundle still contains the pre-rendered export as high resolution image files so that you will be able to use them all.