Thunderbird Outlook Import and Favourites folder setup

First of all, Thunderbird is a vast improvement over Outlook, so I'm persisting in setting it up. Unknown to me when I researched Thunderbird, it had an "Import from Outlook" feature. Well this trolled through all of the PST files on my computer and succeeded importing a fair amount before quitting saying that the errors were in some error-file that I can't find (''Does anyone know where this error file is located?''). So I have a large amount of what I need imported. Strangely, some folders have nothing initially then some time later, the emails are there! But I find the "Favourite" setup annoying. Thunderbird mirrors the setting of favourite with the target folder when you drag it to a higher level. In contrast, Outlook just creates a link to the target folder in its original location. I find Outlook's approach a lot better but still not worth the move back (''Is there another way to create a Favourite in Thunderbird that does change the original folder?''). Thanks for any help.