My average time per 500 word article is 1 hour and 50 minutes, so I'm well under your requirements there. Most of the topics you've listed interest me, and those that don't won't be challenges.
That's why I'm the best bet for this.
Now, as for your tight two-hour deadline - I don't so much have a problem with that, as long as our timezone's aren't overly strange. I won't be getting up at 2 a.m. to have an article into you for 4 a.m.
But if we can set up an agreed upon time, then I can be right here at my desk when you hand it across, and we can even turn the timer on if you're amenable, and you can time me in between articles.
Now, a little about me. I'm a native Canadian English speaker, with a vocational and education background in journalism, which means that I work well under pressure, providing top quality, plagiarism free work, work. I'm building a reputation on this site and in other places for this, and you can be part of this. All you need to do is hit me up in chat, we'll talk about the project, and then I can get started.