Thks Tottally for the tip... But yes I'm aware of the basic debugging techniques.
Just for the record... things are working OK now. The issue was that the 1st I tested sourcing the Java scripts from the webpage itself and the test page I had prepared was DLing quite a bit, (since I am on a Pi with Poor Wifi signal the connection is bad, sometimes I even loose the remote ssh connection... yes, I know... I should take care of it! 
) and I didn't wait long enough! (it took quite a few secs)...
So I immidiately changed into sourcing the scripts locally, thinking something was wrong 
and the error was another one now... A simple '/' beggining slash was the issue. 
As a ref for others I'm posting below the basic flow test and just the snippet of template code. Don't forget to add echarts folder to a public folder/library of yours (after defining it in settings.js httpstatic part if you have not done so yet):
<script src="/echarts/build/dist/echarts-all.js"></script>
<div id="chart" style="width: 400px; height: 300px;"></div>
<script>
var chart = document.getElementById('chart');
var myChart = echarts.init(chart);
var option = { ...here you set your graphs options... }
myChart.setOption(option);
</script>
Thks for the help anyway!
