if I signed up for a bunch of article directories using the same pen name, can I submit a similar article to all article directories or do I have to reword the article for each different article directory? Thanks.
You can submit, but what i suggest you is not to submit same article in more than 50 articles directories. Publish that article on your websites, ultimately Google likes unique content and through that you can get rankings also. It's not advisable to distribute your own unique contents over the web
you can use same pen name in different article directories and you can submit same articles in different article directories. But in anchor text use different keywords.
For what it's worth, I always try to submit an article to 10 or so high PR, low (relatively speaking) Alexa rank directories... I think I've probably submitted a couple hundred articles (salvaging stuff from old computer books I've written in some cases). Get 2 or 3 links an article, and the numbers start to add up. I'm not sure, quite honestly, how effective the articles are. My sense is that they work okay but not great for terms that aren't super-competitive... Like somebody said here (I think) I also for intuition reasons try to mix up the anchor text a bit...