Currently I have an old website with some pages that rank pretty highly for keywords that I'm interested in developing. They do not have any backlinks at all. It ranks at 74 currently.
My question is, if i change the existing content of the page could I lose the ranking? (even if i purposefully optimise the page for the particular keyword)
If I start getting backlinks to this page do i need to make sure they are from pages with relevant content for the keyword?
I also have an old tumblr account, it ranks pretty highly, but was a personal one and didn't have content relevant to the keyword. It does have links, including those from .edu domains which have nothing to do with the keyword.
If I edit my tumblr account to be relevant to the keyword it will no longer be relevant to the content of the .edu links, does that matter?
This is a really small scale project and the key term isn't very competitive, but I'm using it as a learning project.