I just use AQ yesterday to combine one complete family. As Bill said, relationships did not transfer for most of them. Had to go fishing in FT to get them linked.
As for not being able to separate incorrectly combined records - nFS Has this to say about how to do it.
"The combine and separate features are being turned off because Family Tree is now available.
Family Tree handles duplicate records in a new, improved way that is incompatible with new.familysearch.org.
If you need to deal with duplicate records or fix an incorrectly combined record, copy the person's name and person
identifier. Then use that information to find the person in Family Tree.
From there, you can resolve duplicate records or make the needed corrections."
Maybe I am wrong, but I believe the old records not moved to FT and will all be deleted, so there is no need to worry about data that had not transferred. What ends up on FT being the only thing to survive, and we are to work with what is there to correct the data for our line - if this is done through FT or AQ, it is up to the individual doing the work.
There are very few records in my line that have possible duplicates, so I haven't had to manage any incorrectly combined record. Unless the example mentioned next counts as an example.
I have come upon a man married to two women named Mary (each with their own IDs), and his children split between the two women. One had another husband and family, so when I took the children that belonged to the other Mary off her file, and put them with the right couple, all I then had to do was delete the unwanted marriage, and everything was fine, both Marys had their right husbands and children. (Except there were children missing from my family since the relationship didn't work from AQ, as stated at the top of this message.)
I did run into a couple that gave a list of one or two duplicates to
check. You could mark the data you wanted to use from each file, and it
would merge. I have not seen any way to fix incorrectly combined record other than to just remove data that wasn't right, and add new data in
its place. Maybe that is what they mean by fixing wrongly merged
individuals. ??? Have to do a bit more searching the help files. :-)
From: Bill Buchanan <genealogistbuchanan@...
Actually the two sites are still linked and there is some exchange of
information. Names, dates and places are communicated, but not necessarily
relationships. The biggest problem is probably combined records, which
cannot be separated in FT.