It's unlikely the unicode issue is caused by Briefcase. What program are you using to open up the CSV files? If it's Excel, you will need to specify the character encoding. The instructions at Arabic language in ODK - #17 by yanokwa will likely help with that.
Let's try Briefcase first and if that's still not working we can look at the publishers. My guess is that you are getting rate limited and that the rest of the records will appear over time. The publishers are better adapted to processing data as it comes in.