If you want to add menu separators, add this code to your userChrome.css file in your Profile folder:

=========================================
/*Add menu separators*/
toolbar {
min-width: 1px;
min-height: 20px;
border-bottom: 1px solid #666666 !important;
border-top: 1px solid #CCCCCC !important;
}
=========================================

If you like small Throbber, add this code to your userChrome.css file in your Profile folder:

==============================================================
/*Always use small Throbber*/
#navigator-throbber {
-moz-appearance: none;
-moz-user-focus: ignore;
margin: 0 !important;
border: none !important;
padding: 0px !important;
min-width: 0;
background-color: transparent;
list-style-image: url("chrome://browser/skin/Throbber-small.png") !important;
}

#navigator-throbber[busy="true"] {
list-style-image: url("chrome://browser/skin/Throbber-small.gif") !important;
}
==============================================================