1) Add this custom css:
li.menu-item.sf-mega-menu > ul.sub-menu > li.menu-item > a, li.menu-item.sf-mega-menu > ul.sub-menu > li.menu-item > span.title {
margin: 1px 20px 0;
}
2) You can try this, but it may have issues with responsiveness:
li.menu-item.sf-mega-menu[data-megamenucols="4"] > ul.sub-menu > li {
width: auto;
}
3) You can’t have 2 + 3 together, it would be an either/or situation. If you’d like them evenly spaced, you would use:
li.menu-item.sf-mega-menu[data-megamenucols="4"] > ul.sub-menu > li {
text-align: center;
}
Hope that helps!
– Ed