Theme optimization, output blocks go through h3 and other keys, how to fix it?

Question

Search Engine Optimization

Actually, the whole point is that the output blocks, there are comments, other sidebars, go through h3 keys, but I kind of know that this is not correct, and I need to draw an output through a div, maybe someone will tell you. Or will he say that I'm doing something wrong?
Although I am sure that everything should be wrapped in a div, and all other keys should be left only for displaying the text of the main article. And no more.

Answer 1

h1-h6 - for headings.
Wrap the comment output in a div/p/span with the same size as h3.