After a lot of work to fix the program I thought I had, but apparently (at least) one bug is left. The forward slash (or solidus…?) ends up escaped in my output (using XDocument). I can make a dirty workaround and scan the entire file after saving, but I wonder if this really is a problem ingame.
According to @sdee, html formatting should not be in the file, but this is old stuff and might have changed? See this post:
This leaves just the text/things/normal usage and http links as \/ in the file. Would this be a problem?