Icons should reappear after you visit a site.

And why would you expect a customized ordering system to be transferable ?

You can open Bookmarks then Right Click and Sort By Name

You Can Open Bookmarks from Bookmarks then Show All Bookmarks then Click on Views and under Sort you have Multiple Options to display your Bookmarks. https://support.mozilla.org/en-US/kb/sort-bookmarks-quickly-find-ones-you-want

Then you have multitude of Extensions to choose from to sorta in all different ways. https://www.google.ca/search?q=firefox+bookmark+sort+extension&ie=utf-8&oe=utf-8&gws_rd=cr&dcr=0&ei=ITL5Wd2_Hoa0jwPy5IagBg

Note : Firefox 57 Quantum release date Nov 14th https://www.mozilla.org/en-US/firefox/quantum/ Note : Legacy Extensions will be disabled and or removed.

Please let us know if this solved your issue or if need further assistance.

You can instead export the favorites in IE to an HTML file and import this file in Firefox if you want to preserve the order. IE probably stores the order in the Windows registry and Firefox uses the order as saved on the hard drive (IE stores its favorites as normal files and folders).

• export the favorites in IE to an HTML file (bookmarks.html):
  File -> Import and Export
• import the HTML file in Firefox:
  Bookmarks -> Show All Bookmarks -> Import & Backup -> Import Bookmarks from HTML

• https://support.mozilla.org/en-US/kb/import-ie-favorites-other-computer
• https://support.mozilla.org/en-US/kb/import-bookmarks-html-file