You do not have to change any of the features but you have to mention all the errors. You need to test:
1. the quality of coding. You need to tell the coding is structured, and well commented.
2. downloading time of the most important pages. Are there any pages that download slowly if a high traffic is simulated.
3. are there any functional bugs. Things that you see as user where the site does not do what it is supposed to do
4. Is the website stable.
I am not very familiar with testing. I hope that form the above it become clear to you that I want a thorough testing of the website.
Would be great if you have any software to do this kind of testing.
If you cannot do it in the budget write me. One thing needs to be clear it needs to be very high quality testing so that you find all the bugs.