Make it possible to select text in a post / page / custom post and hit a tinymce button to turn the selection in to a snippet. Snippet would now be in snippet section and selection on the page would be replaced by the shortcode instantly.

Select a snippet in a post, page or custom post type and select break out to replace the shortcode with the snippet content

Add place holders to snippets. Say {post_title} etc. All the obvious post meta plus custom fields would be good. Could select placeholders from all the field in the database.

Example.

If you found {post_title} userful why not read other articles in {post_category_name} and sign up to our rss feed

Make Relevanssi-Search-PlugIn work together with "Snippets".

I fact, whereever I use a snippet the search doesn't work anymore...