Hi,
These modifications you require can be mostly done with some custom CSS, for example:
1)
.full-center nav#main-navigation ul.menu,
nav.std-menu ul.sub-menu {
font-weight: bold;
}
2)
Do you mean your subnav items? If so:
nav .menu ul.sub-menu {
background-color: transparent;
}
nav .menu ul.sub-menu li.menu-item > a {
color: #fff!important;
}
3)
What icon are you looking to add, a fontAwesome one? If so, add the icon code after the menu text within the menu editor. http://fortawesome.github.io/Font-Awesome/icons/
4)
This would change it globally, so page like this: http://new.inspiragraphics.com/portfolio/ would not look good. Do you want it just on the homepage?
Thanks.