Question: Does inline CSS and JavaScript really affect site SEO?

Answer: 
Hardly. What counts for a search engine is textual content, it will filter out everything else.

I assume CSS comes into play with search engines when they determine whether a portion of text is visible on the page, or hidden for the purposes of SEO. But even there, whether the CSS inline or in a style sheet won't make a difference.

One could argue that the more CSS and JS a page contains, the less weight do search terms have on that page. But I think that argument is invalid, because any non-content content will simply be ignored altogether.
Search Engine mainly read textual part of the website.But there are many factor that include that effects seo. Using table template, and even using inline css make the page load time a little more. even if you can check on html validators it marks all inline ccs as error.Slower responsive time for site.