• The message editor multi-line text box background only displays a single line - either make this expand dynamically, or make it several lines with a scroll frame.
• Add click handler in (or on top of) the scroll child to redirect widget focus to the text editor

When I paste multi-line text into the message box, it only "barks" the first line to the channel selected.

Is there a way to get the message that goes out to be multi line?

When I paste multi-line text into the message box, it only "barks" the first line to the channel selected.

Is there a way to get the message that goes out to be multi line?

Unfortunately, no. It is a limitation of the way chat messages work in the game, they will always truncate the message at a newline. There is no way around this.