Have you tested NewsAssist? It definitely belongs in your list of tools. It is a free firefox-addon that boosts the productivity of bloggers and editors. It is a great tool that combines searching, editing, publishing and distributing blogtext. NewsAssist is a powerful tool and a great working environment that is fully integrated with FireFox. It can be found on www.newsassist.org and on the firefox add-on site.

"free blogging tool": http://www.newsassist.org