I purchased a marketplace theme. I installed the Theme

Hi, I purchased a marketplace theme. I installed the Theme Check plugin. When I ran it on my site, there were countless (maybe over 100) warnings and recommendations. I then went to http://www.themecheck.org, and uploaded the theme there. The theme got a zero score. I wrote to the theme company. They told me that the theme is fine. There are things that Theme Check picks up as wrong because the theme is not a general blogging theme and it doesn't use just simple coding like other blogging themes. That is why it appears like there are so many errors, but actually there aren't.
Can I get a second opinion on this, please? Should I buy a new theme or is he right?
I really like the theme and may not be able to afford a new theme. Is it possible to fix these errors? Any input will be appreciated.
Thank you.