Thank you for the appreciation for the the theme.
Regarding your queries, we are not quite clear of “parent / child” pages “not working” in the theme.
The parent child page property comes from the default WordPress action and the theme accomodates the feature. If you are willing to create dropdown of child pages under the parent page in the menu bar, you can do it by simply setting the menu hierarchy from the Admin Dashboard > Appearance > Menus. If your requirement is anything other than this, please explain to us further your requirements so that we could help you further.
Regarding the GTranslate widget placement, as per the theme design the theme does not have the widget area in the header of the theme.
Although it is possible for you to achieve your request on the theme with code customization of the theme, it might effect other parts of the theme, like its design and some time its functionality.
It would be wise not to touch the code yourself if you do not have knowledge on programming,
Our suggestion to you is to hire a professional developer for your customization, so that your theme will no be effected in any way.
To hire a developer please follow the link below
We hope it helps,