Hello,
If you make everything in right way you should not face broken site.
Unfortunately, site optimization is outside the scope of our support. We have some users who wrote us about site speed but every site is individual and site speed optimization depends on many params. In our topics you can find main tips but if you need individual help we would recommend you to contact with WPKraken.
If you are not satisfied with site speed and think that our theme is the main reason of this we can give you refund.
Regards