The current userChrome.css (2)

/* No "New Tab button" abomination */
.tabs-newtab-button {display: none;}

toolbarbutton.bookmark-item {
  height: 0px !important;
  /* font-size: small !important; */
  margin-top: -3px !important;
  color: black !important;
}

/* Remove the Bookmark star */
#star-button {
display: none !important;
}

/* Remove splitter between the URL and Search bars to save space */
#urlbar-search-splitter {
display: none !important;
}

/* Hide toolbar borders */
menubar,
toolbox,
toolbar {
border-style: none !important;
}

toolbar {
-moz-appearance: none !important;
}