Which "search and replace tool" did you use? The one recommended by Wordpress? And why did you rename the plugin folder?
You followed the instructions here?
When Your Domain Name or URLs Change
When your domain name or URLs change - i.e. from http://example.com/blog to http://example.com, or http://example.com to http://newexample.com - there are additional concerns. The files and database can be moved, however references to the old domain name or location will remain in the database, and that can cause issues with links or theme display.
If you do a search and replace on your entire database to change the URLs, you can cause issues with data serialization, due to the fact that some themes and widgets store values with the length of your URL marked. When this changes, things break.
Verify that all the values in wp-config.php are correct. If you are getting blank screens, I assume you cannot log in to the admin panel to change the domain/URL settings. Can you? If you can, disable all plugins. Disable any permalinks you might be using for now.
If it still doesn't work, then you will have to do the tried and true method of seeing how far you get before trouble starts. Open a file, put in a PHP echo statement stating "I made it this far." and if that doesn't get output you know the trouble is higher up.