In your code the following line

use constant kParaSpace => 4;

appears to be the setting for the gap between paragraphs when the paragraph tags are used.

When I tested your editor the gap between paragraphs is rather wider than seems to be the norm in most PerlMonks posts. Perhaps kParaSpace should be set to 2?

This is a minor nitpick; otherwise this is very slick. Kudos to you...

Scott

PS: This node was written (mostly)using your editor:)