@juliet we fixed the issue which caused the circles in step 3. Let me know if there is anything else you stumble upon.
As for H4, 5, 6 - heading levels define the structure of the content of the page:
H1 - what this page is about
H2 - title of each section
H3 - the titles of each subsection
etc.
From the research we did we found that pages with more then 3 hierarchy levels are very rare (home page of nba.com and nytimes.com don’t get to h4), so we decided to keep it simple in the wizard, and offer only what you’ll probably use.
That being said, you can always define from the component itself any hierarchy level you want.