1) This is not supported in the power store side menu.
2) in the webassist/plugins/side_menu/nested_accordion/accordion_styles.css file you can change the padding-lef for the second group in the following selector, you may need to adjust the other groups if you have sub catagories.
dl.nestedaccordion dd dl dt {
padding-left: 45px;
background-position: 20px 0;
}