Mobile SEO refers to the on-page optimization for mobile users. This include making it mobile friendly, having low data content, small fonts and easy mobile navigation!
Maybe you can try ahrefs and check those metrics to see how popular will your site be. Alternatively, just log in to Google Webmaster, go under search queries to see how well you rank for certain keywords
Cheers.
I chance upon this application optimizely by some past google developer that can help you to optimize your website layout. I think in on the outset, you have to know what is the issue as pointed out above; is it irrelevant traffic or poor design?
Pretty hard to avoid keyword stuffing or to obtain optimal keyword density of your site. I would suggest you write naturally and tweak it slightly afterwards.