crgeary

This plugin reinstates the content/wp-editor field that was removed from the “page for posts” page in the 4.2.2 update.

Add Editor To Page For Posts

Reinstate the WP Editor on the "page for posts" page.

maisdesign

It disable Post editor for Non Administrators and let you create posts only using Custom Fields (remember to configure them first!) 
It uses: if ( ! current_user_can( ‘install_plugins’ ) )
Actually there is no Admin Panel for this plugin if you would like to change minimum permission or role you’ll have to change it manually via FTP
<h3>Feature Request</h3>
Any feature request? Drop me a line: marco@maisdesign.it
This plugin is based on a conversation here: 
<a href="http://wordpress.stackexchange.com/questions/45113/how-to-disable-edit-post-and-allow-only-custom-field/45158#45158" rel="nofollow ugc">WordPress.Stackexchange</a>

Editor Remove

It disable default Post Editor and let users like Authors and Editors (not Admin) to write posts only using custom fields.

Add Editor To Page For Posts vs Editor Remove