Are you asking me about WikiTree guidelines...? What do you mean about mixed writing? Do you mean some Japanese/Chinese characters and some using the Roman alphabet? I don't know, but I feel it would be wrong...
At a glance, I see something a bit wrong in that file - it's probably not a big deal, but I do see lots of these. Here's one example:
日本兵庫県城崎郡香住町 日本,兵庫,県城,崎郡,香住,町
The first part of that is the location -
日本 Japan
兵庫県 Hyogo-ken (ken=prefecture)
城崎郡 Kinosaki-gun (I think) ('gun' is a smaller area)
香住町 Kasumi-cho ('cho' literally means 'block', though this could also be 'machi' which means 'town')
What I'm noticing is that the commas on the right are not correct. (日本,兵庫,県城,崎郡,香住,町) This is being broken down in the wrong places. In terms of parsing the locations, if you need to do that, this may cause problems. If you don't need to worry about that second column, then maybe you're OK.
Another example:
日本奈良県葛下郡高田町 日本,奈良,県葛,下郡,高田,町
県 is 'ken' (prefecture) and it should be at the end of 奈良 (Nara), rather than connected to 葛. The next comma is a big mistake, too, as the next part of the location is 葛下郡 - Katsuge-gun (I think). You can see the same '郡' as in the previous example. Then again it has '町' separated from the rest of it (it should be 高田町, which I assume is Takada-machi, though it could be Takata or -cho)... It's a tricky language to read.
Anyway, I hope that helps.