yes it will help the ranking of your other pages and also of the whole domain, but don't abuse the use of the same keywords over and over again, because you will risk to get penalised and your ranking get decreased. more important that the internal links and titles, are...
Alexa Rank is based on visitors and backlinks and it's not consider On-Page SEO. Google Rank is calculated on both Off-Page and On-Page SEO (responsive design, page titles, descriptions, content and validations are relevant). However, google rank is very slow to increase (in my experience); if your site is online...
According to google, if your site is not mobile-friendly, it will lose ranking on mobile searches, but desktop searches will not be affected. Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will...