Thunderbird 24.6 just stops working . . . all the time.

Question

I've hinted at some of this before, and I've searched the forums for help . . . alas!
We have an iMac running 10.8.5 and Thunderbird 24.6. We've been running Thunderbird since it was Netscape and before . . . it's our primary email program and we have TONS of accounts all filtering through. In this incarnation, I see emails from 2006 so it's been actively working, pretty much non-stop, for at least 8 years. Now it doesn't!
It launches fine, retrieves what it's supposed to retrieve . . . all POP and imap accounts work . . .everything's fine. And then, it stops. The first sign will be something like it not deleting a message when you highlight it and hit delete. (Doesn't make a difference if it's the keyboard delete or the button in TB.) Next, and more annoying, is it'll get stuck on the "saving email to sent" function which means I have no way of knowing if the email's actually gone out.
This happens regardless of whether I start in Safe Mode, modes with everything turned off, reset everything . . . whatever. It all launches and starts fine and then just stops.
I've gone through and emptied all the trash/junk folders; I've compacted everything I could, everything's disabled . . . nothing seems to help. I hate to abandon TB after all these years . . it's got ALL of our various email accounts (75 of 'em) in there, all the subfolders we've set up over the years, the various filters -- time consuming/convoluted ones set to manual so it won't slow down things too much -- and it's been great. But, obviously, I can't keep restarting every 15-20 minutes and, at the minimum, need to know that my "sending" email works when I need it to work.
The only thing thats show up in the Error Console are:
Could not read chrome manifest 'file:///Aplications/Thunderbird.app/Contents/MacOs/chrome.manifest
-and-
While creating services from category 'profile-after-change', could not create service for entry 'Disk Space Watcher Service', contract ID '@mozilla.org/toolkit/disk-space-watcher;1'
Any advice at this point would be greatly appreciated.
stu

Answer 1

Well, even though it appears I'm just talking to myself here, I thought I'd keep the update going. That way, anyone else going through these issues, might see they're not alone . . alone . . alone…one…one…ne…e
Thunderbird v31 was worse for us here. In addition to the problems listed in the original post, some of the functions weren't working correctly and, after some discussion, we decided the best thing to do was go back.
We completely uninstalled Thunderbird, reinstalled v24.6 from scratch, copied over the old profiles/folders, reimported the various mailboxes, and that seemed to fix things. We run NO extensions or plugins and have a few little quirks . . . things like having to approve graphics in emails even though we've marked them "always load," addresses in our address books not autofilling, various mail filters not running automatically . . .stuff like that.
Obviously, something got installed along the way and messed up a few things but, at least, TB 24.6 stays on now and basically works.