Hi Dave, I understand your need for the list of directives. It is definitely something that is on our agenda. In the meantime the examples are a pretty comprehensive resource if you read through them.
There is no need to use AmCharts for what I was suggesting, I was suggesting to use something like the vertical bar from the "bar display" example. The example just couples plain HTML elements with CSS styling. Take a look at the style sheet which is linked to from the example to see where the border radius is used. I was thinking you could set the border radius to a larger value to give it more of a tank like appearance (make it wider too).
CSS is a web standard used for styling elements on web pages - see here https://developer.mozilla.org/en-US/docs/Web/CSS
Or more specifically for the border radius property - https://developer.mozilla.org/en-US/docs/Web/CSS/border-radius
We do intend on making it easier for laymen to create and manipulate dashboards, unfortunately at the moment if you need to create customized components you will require some web development knowledge.