How is this done? Now I personally use fulltextrssfeed.com and Wordpress robot, however i don't enjoy it, because fulltextrssfeed.com posts only like 5 articles if this was a lot more than 50 within the original Feed. And all sorts of the plug ins I examined (FeedWordPress, RSS poster, Wordpress-o-matic, Wordpress robot) could not publish full articles of the many feed I made use of.

The feeds themselves don't retain the full text from the articles. What fulltextrssfeed.com does is fetching the Link to the feed entry and removing the entire text after that. This is exactly what you need to do, too - if you would like all of the articles