@stackoverflowuser the template will be the themes templates folder and if there is one thats overriding the default one it'll be called user-login.tpl.php Is the site available online somewhere so we can take a look and inspect the page?

the only other thing I think can of is do you have a custom template file for the login page do you? If so remove that, clear cache and try again.

if you've got drush installed you can use drush uli admin (or your admin user name) in command line. copy the link into the browser and you should be logged in, you can then put the block back etc.

the login block & login pages are not linked in that way, have you tried in another browser or clearing cache?

If you're using pathauto you may need to update and re-generate the alias' go to url alias' in config & bulk update tab. You may also need to check that the Generate automatic URL alias for that content is ticked.

it'll likely be something you may need to configure within CKeditor for the Insert Button to appear on the toolbar. You can configure such settings by going to yoursite.com/admin/config/content/ckeditor

For the role of authenticated user you're want to de-select all permissions and give permissions to your other role. You could probably create a rule if the user doesn't have role impact protection user deactive them. This way they won't be able to login.