With what hook do I remove WooCommerce existing Product Data Tab form fields?

You find the code for the general tab in the file includes/admin/meta-boxes/views/html-product-data-general.php. In this file WooCommerce defined some do_action hooks. Maybe your plugin used one of them. Hooks: woocommerce_product_options_pricing woocommerce_product_options_downloads woocommerce_product_options_tax woocommerce_product_options_general_product_data

How to I prevent WordPress from switching external HTTP links to HTTPS?

I suspect a bad plugin, but you didn’t provide enough information. But it could be a directive in your htaccess file that is not correct. Take a look at this question/answer for a comprehensive discussion about it: https://stackoverflow.com/questions/4398951/force-ssl-https-using-htaccess-and-mod-rewrite . If that doesn’t help, provide more information about plugins and your htaccess file contents.

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