Theme migration and small edit

Developer needed - switching my site to a new theme, and adding a small feature.

I've been trying to migrate my site from one theme to another and it's simply taking too much time. I'm trying to move ---------- (currently using the theme Listable) to a theme called List Go ( ---------- ).

The kind of site I have is a review site, like a much less complicated version of Yelp or Tripadvisor. The reviews that users leave are of the utmost importance.

There are two difficulties:
1. I've figured out how to import all the listings from one theme to another, but I also need to import the reviews. The tables for the reviews is different between the themes.

2. I need admin to approve new reviews before they go live. This is available on the theme I have now, but not on the new theme. I need someone to add that feature for me, maybe through a plugin or adding code to the child theme.