Hi jason_borat
Thanks for your email. GE-Graph provides you with complete control of the bars appearance.
To make the bars shorter you have to uncheck the Height's "automatic scale" box and decrease "Height factor" and/or "Altitude to add".
To make the bars thicker:
1. If you want the width changing according to values then uncheck the Size's "automatic scale" box and increase the "Size factor"
2. If you want a constant width then check the "constant" box in the Size option at the top of the form, and enter your width and choose a unit in the Size options at the right of the color options.
Let me know if you need further hints.