The first step in any SEO is on-page optimization and installing proper tracking on the website if it's missing. There is a lot to do in on-page optimization that goes beyond just editing page content and titles or anchor text. Our SEO’s will require FTP access for many things like uploading Sitemap, etc. There is nothing to worry about as we will just be doing our job.
So Admin Dashboard details are mandatory and the process is impossible without full access.
The Process will be 100% safe as we have a Non-disclosure agreement which is drafted by our lawyers that we will provide before initiating the process.