The map download folder or map custom folder is located in your user documents folder. This is the default Warcraft 3: Reforged map location folder. Please note that <YourUserName> must be replaced with your windows username.
Warcraft 3: Reforged BETA was not released for Mac yet.
You can leaf through all types of chat rooms by putting the cursor into the chat field and pressing the tabulator key or "TAB" key. In this way you can choose between: