Successfully imported json bookmarks file into FF19, and library view shows folders correctly, but Sidebar view shows no folders and so loses my organization.

Question

Longtime FF user. Still on 3.6.28 mostly, due to my need for my large collection of hierarchically organized bookmarks. I have 2000+.
Trying FF 19 today.
Successfully imported the json file from other system.
Via the Bookmarks menu, Show All reaches Library view and everything is there. Except for the fact that this FF design will not let me see the contents of more than one folder at one time. Which is why I've stayed with 3.6.28.
Now, a friend has shown me that I can see multiple folders AND the contents of multiple folders using Sidebar Bookmarks, just as I wish. Great! But after importing my bookmarks, all I see is a random list of bookmarks in the Sidebar view. There are no folders or subfolders so with this view I lose all the organizational structure I see in the Library.
Am I missing something? Is there a way (an addon) that would put everything in the Library Right Pane? instead of just one folder? That would be fine.
OR
Is there a way to preserve the organization of my bookmarks after importing them, in the Sidebar view? That would also be fine.
Thanks for any helpful answers. Otherwise, back to 3.6.28 I go.

Answer 1

In the Library view, everything functions as Mozilla would have it. Yes, individual bookmarks are not to be seen, except in the right side pane. And only from one folder at a time. Returning to the beginning, that was my complaint with Show All Bookmarks and why I've stuck with 3.6.28 coupled with Old Manage Bookmarks.
And that's why I asked if anyone is aware of an addon to make the contents of more than one folder visible in the right hand pane of the Library view in FF 4 and up. I've even tried Mike S's "hack" of OMB to see if I could make "Organize Bookmarks" return on FF19. No luck.
So Library View works as it "should". But that's insufficient for my needs.
You've indicated that Sidebar view SHOULD function as I wish. But so far, barring a fix, I don't see folders, subfolders nor individual bookmarks ''in the order'' that they started in, from PC1. I don't know why that failed. I'm happy to keep trying things, til the moon turns green.
Proceeding along -- sort Library? Yes, sorting works. But since the Library is functioning, unsorted is my preference. To make the Library View FULLY ADEQUATE though, I'd want to see bookmarks in different folders viewable at one time. What I need is the Sidebar view with all the folders showing, replicating the Library's View hierarchical structure.
HTML export and import? I'm sure I can import one into FF19. But I don't know how to export them from PC1 as my bookmarks are in .json format. When I try to do that, the dialog window confines me to selecting an HTML file, and so I can't export the .json file I have. I'm sure there's an easy answer, but its not intuitive.
Thx
P