Please do the workflow below,
1) Select the style in the styles palette
2) Click Edit button on the style editor palette
If you want to duplicate the current style, click Copy icon
If you want to edit the the style, please work in style editor for "Add style element" "delete the style element" "edit the style element by clicking the tab"
Your question about roughen editting, you can click the tab of Roughen in the style editor to open the panel, then it can be editted.