Some admin pages are available based on the options in Admin > Permissions. For example the moderating options open up the Admin > Moderate page.
To allow editing general options the user needs to be an Admin.
If you want Editors to change only some options the best method would be to write a custom plugin. A Page plugin should do it. Take a look at the example that comes with Q2A which shows how to make a form. Then check the user is an Editor when viewing the form and on submission.