We are expert developing quality themes since 2008. We are well aware with latest market requirements. We will go through different phases to inspect your theme.
1) Code check if there is any extra code increase load time and use more sources.
2) Code Security to check if coder left any vulnerability which can risk the security.
3) If the images and the icons used in theme design are properly resized and cropped resonably.
5) If the future wordpress or any other plugin update will break the theme. If theme provide updates the child theme set properly.
6) The user who is using theme have enough better options or theme can be enhanced more to provide better user experience.
7) Is theme 100% SEO friendly.
8) Is theme built completely secure, and speed optimized or need some attention.
9) If the theme is All browser compatible.
10) If the theme including any extra js, css, or images which is not being used in theme.
11) If theme follow all w3c Standards. And Schema is correct for required portions.
12) Unlimited answers to your questions would be answered on our Report.
We will provide detailed feedback on theme. With help of screenshots. This would be really worth service to get.