This is currently not easily doable. You would have to go to the installation directory, and from there to "/mods/d2k/rules/campaign-rules.yaml" and change "FogCheckboxEnabled: True" to "FogCheckboxEnabled: False".
Fonts are referenced in the "Fonts:" section of "mod.yaml", so you can add a font there. You probably want to replace the existing fonts with your own font files. (Otherwise you then need to change the relevant "Font: <font name>" entries in the .yaml files inside the "chrome" directory. Which is do...
You can compile it by downloading, unzipping and running the "make.cmd" (or just running "make" if you're on mac/linux). But that plugin will be severely out of date and not work with the latest OpenRA version without updates.
There's a bug on Windows that the hardware cursor support sometimes fails. This can cause laggy cursors until a restart of the game (where it will try to use hardware cursors again). The next release will improve this situation.