We're aware that using multiple H1 header tags on a page is not good, but what about multiple h2, h3, h4, h4 & h5 tags. How many are allowed on a page before it gets saturated? Is it best to only duplicate h4 & h5's?
Think of the header tags as different headings within an article or term paper. Typically you will only have one title (h1) for your article or term paper, but you might have lots of different sub headings (h2, h3, etc.) for different sections or parts of your article. So it is fine to use as many h2, h3, etc. tags as needed to help break up your article or page logically. It is good practice to use them hierarchically though, meaning h2 follows h1, etc., rather then using a h3 directly after a h1 tag. If it makes sense to use them in your page, and you are not trying to use them to stuff keywords, then I would not worry about how many I was using. Like you said though, it is best to only use one h1 tag though.