Exporting and importing my WordPress database, but none of the plugin settings are importing

Very likely your settings are there but during your find and replace in sql you may have corrupted the serialised options.

If you are doing a mysql dump from site #1 and importing dump to database for site #2, you might want to use my WordPress migration script.

Using the WordPress migration script you can have all the options updated with one click, migrating all your settings for plugins, themes, widgets and other options.