Hello,
01. The quantity input is actually displayed correctly for variable products on your other products. But I’ve checked the product you shared in the screenshot.
The reason you’re not seeing it on your end is that, for that product, you’ve enabled stock management in the Inventory settings and set the stock quantity to 1. When the stock quantity is limited to 1, WooCommerce automatically hides the quantity selector to prevent users from selecting a higher quantity than is available.
To show the quantity field, you can either increase the stock quantity to more than 1, Disable stock management. https://ibb.co/Tqr744dV
02. These plugins are not required for the Woodmart theme to work. They are likely bundled with another theme or plugin previously installed on your site.
Best Regards,