We have multiple domains on the same C Block IP Address. Our main site is an eCommerce site, and we have separate domains for each of the following: our company blog (and other niche blogs), forum site, articles site and corporate site. They are all on the same server and hosted by the same web-hosting company.

They all have unique and different content. Speaking strictly from a technical standpoint, could this be hurting us? Can you please make a recommendation for the best practices when it comes to multiple domains like these and having separate or the same IP Addresses?

Thank you!

Is it better to optimize based on search volume or click through rate? For example:

If a keyword has a CTR of 19% and only 3,000 monthly searches, while another keyword that is relevant to that page has a CTR of 0.7% and 20,000 monthly searches, which keyword should that page be optimized for for better natural results and the bottom line?