I'm not sure what you mean by "broken", but all my tags with slashes that did not work in Delicious are now working fine in Pinboard, the only thing I did lose was the tag bundles, and I had to delete three mystery tags that showed up out of nowhere.

I used to save fic on my hard drive, and then completely forget about it. (Also, the files used up a ton of space. That new save to PDF option on AO3 is heaven) The archiving sites make it so much easier to search by subject or author. But then again, there's the risk someday a specific page will be deleted. I guess there are no perfect solutions.