Thanks for your question.

So the question or feature request goes like this - is there a possibility to make some kind FD backup feature witch is storing You icons, background image, sorting order etc to some kind of backup file ? Like some kind of extra folder like this //FirefoxPortable\Data\profile\fastdial\backup//

This kind of feature is used by Speed Dial,

To keep simply to your question, no.
You see Fast Dial is backed up to places.sqlite, which is Firefox Bookmarks.
However of course you can back up your whole Firefox Profile very easily with FEBE.

However I was under the impression that XMarks had a backup facility of its own that involves storing information with Xmarks.
You know here
Backups going back 3 months

As all Fast Dial information is stored in Bookmarks (except Fast Dial Background) you could of course also restore a previous Firefox JSON automatic backup of bookmarks...

BUT - over a period of time I have encountered a problem - the culprit is not FD actually but looks like FF himself with Xmarks. Some times FF or Xm goes "crazy" and resorts my links in Bookmarks FD folder. This results that all my ORDER in my maine page goes BUUHFF. And I need to start resorting them again.

OK this leads to another question, are you using Xmarks to synchronise Fast Dial.
If you are not then you could change the name of the root folder in Fast Dial, and in that way it would not be synchronised, so could not be changed by xmarks.

But more to the point it would be interesting to discover why this problem is happening.

I would be interested to know, when the bookmarks get scrambled have you checked the sort option in Fast DIal to see if it has been altered.

Also worth checking is if you are in the right folder in bookmarks.
To make sure you are right click on the Fast DIal folder in Bookmarks/Organise Boomkarks/Bookmarks Menu/Fast DIal and go Fast DIal/Make Home.

Please let me know if any of this makes any sense to you...

So - did I understand right - You telling me that I should move out FD folder from Bookmarks ?

No... not at all... !!!

Xmarks synchronises automatically Folders in Bookmarks of the same name.

So a Fast DIal Folder in one machine will be synchronised with another Fast DIal Folder in another machine.

If for example you rename your Fast Dial Folder as Root, and also make sure that Root is home, in one machine only, then this will stop Xmarks from synchronising with the Other Fast Dial folder in the second machine.

Not sure how things work though with xmarks.com...

Please let me know about all this, and whether it makes any sense..

The fast dial folder (even if it is renamed) has to be in Bookmarks Menu in bookmarks (bookmarks being places.sqlite), as that is where the extension backs up to.

Please if you rename or create another folder in Bookmarks Menu with a different name then you need to make it the Home Folder.

Maybe try all this first in a new profile just to be sure you do not mess anything up,,,,, !!!

many thanks