First Visual composer is already included in the file you bought so you do not need to buy anything else.
Second there is nothing wrong with almost every file on here (thats why it is the biggest marketplace on the net). That error could be several things but you should email the author http://greatives.ticksy.com/ and am sure they will help you
Typography really needs a LOT of attention throughout especially some of the font choices and the consistency.
I am not sure your nav and search bar aligns properly to the page
The whole design needs to breath more and be spaced better
Your team member names are spaced but do not align to the images on all of them
The ledge below the section titles that sticks up into the title bar does not work
Spacing is very inconsistent e.g. look at title bar height for blog .v. services or others
There is nothing unique to the design really
Footer could be improved