Local seo question about iframes and NAP

Quesitons:
How do i add iframe into the page.
when i did add it in. It iframed it but when its loading the page or when clicking on a different page. It disappears for a second revealing whats behind it and then reappears.

i was using this code:

<iframe src="http://www.source.com/desired_page.html" style="position:fixed; top:0px; left:0px; bottom:0px; right:0px; width:100%; height:100%; border:none; margin:0; padding:0; overflow:hidden; z-index:999999;">
Your browser doesn't support iframes
</iframe>

that i found here http://www.blackhatworld.com/seo/question-about-iframes.850835/

What code should i use?

2nd quesiton: will iframe hurt ranking?

3rd question: How important is NAP? what would boost me more into rankings, NAP or just 1 pbn

Thanks for anyone who replies to this

Anybody?!?!

My 2 cents.

NAP is must for local rankings.NAP consistency is no more an additional step, its incorported in local SEO DNA.
Having a consistent NAP works for me most of the time. A PBN occasionally for high competition, does the job.

Please ignore, if I got your question wrong or my reply doesnt make sense.