Hi there,
You can add a button shortcode to your tab content under the text, like from here http://demo.theme.co/integrity-1/shortcodes/buttons/
About the alignment and spaces, please add this CSS to your global custom CSS.
.x-tab-content .x-tab-pane {
padding: 4% 0 !important;
}
.x-nav-tabs>li {
text-align: left !important;
}
.x-nav-tabs>li>a {
padding-left: 0 !important;
}
Thanks!