How to remove price, add to cart, and quantity choice from all product pages?

@JacPainter

Replace your CSS, make a copy somewhere, with the following.

<style>

  .product-price,
  .product-quantity-select,
  .show-product-price #productList .product .product-price,
  .sqs-add-to-cart-button-wrapper {
  
    display : none;
    
    }
    
  </style>

Let us know how it goes.