Are there any (minimalist) magazine, newspaper, or journal templates for ConTeXt?
Ideally something with a lot of graphical elements.
The concept of “templates”, which already has a rather vague definition in LaTeX, doesn't exist in ConTeXt. In that regard it is more similar to Plain TeX, because you just roll your own layout from scratch and actually it isn't that hard. In contrast to Plain TeX, ConTeXt offers a lot of high level interfaces for things like adjusting the page dimensions, etc.
As you already noticed, there is little info available about sources to learn from. I can recommend to you looking at the following sources:
This is the best and most comprehensive ConTeXt tutorial I have come across yet! It teaches you exactly the workflow how to roll your own layout. I am deeply indebted to Aditya for creating this awesome resource. In my opinion this is the best way to learn about ConTeXt and great for beginners.
An updated version of “ConTeXt, an excursion” which was written in 1999 for the Mark II version ConTeXt. It is a bit incomplete and touches most concepts very superficially and also features some outdated features, but gives a nice overview of what commands are availabel.
This page on the ConTeXt Garden wiki accumulates all the manuals which exist for ConTeXt. What is more important is that the sources for all the manuals can be accessed online: http://context.aanhet.net/svn/manuals/ This probably comes closest to what you are looking for. In principle you could copy these layouts and plug in your own content. Soon you will realise though that the ability of creating you own layout brings more flexibility and freedom and allows you to express your creativity.