All-in-one-SEO or Atahualpa?

Hello - I'm currently using 'All in one SEO' for my Atahualpa themed blog. I'm having difficulty getting people to my site though for the main keyword I want.

My website is: http://www.griefermadness.com and I want it to be the first result when someone types 'griefing' into a search engine.

I'm considering getting rid of the SEO plugin and just using the Atahualpa built in one, which would allow me to use "Make Post/Page Titles H1" which I feel would impact my search rankings. What are you thoughts on this everyone, or do you have a better suggestion as to how I can rank better for the keyword 'griefing'?

PS I should mention that almost EVERY one of my posts, as well as their descriptions, have the keyword 'griefing' in them, which is why I am confused it's not showing up in the search engines!