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Are keywords in titles and headings interchangeable or do they have to be in the exact same order as per google adwords. I am trying to naturally combine 3 keywords in my title, h1 and h2 to rank for all 3. Would each of the 3 individual keywords have to have an h2 in the content? Is this safe...

I have a client who has a gigantic site. He was lacking basic SEO on his home page, yet is ranking quite well. He doesn't have an h1 tag on the page, and I want to put it on with the keyword. However, his css for h1 is a weird gigantic purple mess, and is used on many other pages in the site...