Only seeing this now... I am not sure, I did it in person but you probably can post it. Yes I would expect a single entry Chinese visa for that. If you were going mainland China then Hong Kong then mainland China you would need a double entry visa. Your passport will be stamped in Hong Kong with the length you can stay. I just put in a very rough route of a few cities, no hotels or anything and the route changed a lot with no trouble when I was leaving. Again it was 8 years ago I was there.
I got all local currency when I entered China so I don't know the limits allowed.