The cause of that error is a movie thread that doesn't contain the proper BB Codes in the first post for a movie thread.
Usually it's a movie thread that's been edited in XF1 and not properly formatted.
The only way to figure out which thread is causing it and why it's happening is to get a copy of your database and throw it on a development server to run the conversion there.
Okay, it is not possible to add collections at this time. It would require quite a bit of additional code to the addon to be able to use the API for the collections.
I don't have any intentions of adding that at this time, but I will add it to the wish list.