I would double check on if you can store your iPhoto library on the QNAP. I do have an older version, I know I can't use QNAP for iPhoto, I get the error of unsupported file format. Just double check to make sure you can.
Most of the QNAP stuff is for the older version of iPhoto.
However another alternative is to make sure the QNAP you are going to use supports the following and you might have to buy another piece of software...
https://www.qnap.com/i/en/trade_teach/con_show.php?op=showone&cid=29