Hi Herman,
For your first question you should open your knowagecockpitengine war and change file column_chart.vm on this path:
knowagecockpitengine\WEB-INF\classes\chart\templates\highcharts414
You need to add this (blue) at 581 line.
#if ($chart.seriesStacking=="true")
, reversed: true
#end
I am not sure that I understand your second question. You mean on space between ~4200 to 4500?
Bye,
Radmila