Securing a Sharepoint Webapplication using SSL.

We have created a dashboard site (using standard edition with windows authentication) in sharepoint 2010. The site is now being tested and I got some vulnerability report from them. According to the report, the site is not in 'https://' and secure,httponly attributes not set for cookies. Now when studying about SSL in SharePoint most of the discussions, guides me to extend the webapplication. The dashboard site has to be hosted as a internet facing site.

My question is do we need the SSL certificate for Sharepoint, if it is necessary do I need to host the extended webapplication internet site rather than the original webapplication(where my dashboard site resides) or is there a way to make the original webapplication have ssl certification.

Should the extended webapplication have its own content DB or it can be configured to have the original webapplication DB. Should its name, port, hostname be different.

Will this be affecting the custom solutions and validations deployed.

I am not a sharepoint administrator, so bear with the questions which maybe stupid or not related. Need your help.