Quantity Field and Limit

-- HikaShop version -- : 2.6.3
-- Joomla version -- : 3.5.1
-- PHP version -- : 5.3.29
-- Browser(s) name and version -- : Safari 8.0

Hi Hikashop,

I want to do something like that:

1) For a certain category I would like to set the Limit to a quantity of 1 forever FOR EACH PRODUCT. By setting the option to "category", customer can only purchase 1 item in that category, but not 1 OF EACH ITEM in that category. I can create a new Limit for every product in that particular category, but would like to know if there's a faster way to set the Limit to 1 quantity forever for EACH PRODUCT in the category?

2) And for the category mentioned, I also like to remove the QUANTITY FIELD of the add to cart function, both on PRODUCTS LISTING page (can be done via configuration, and have done it) and PRODUCT page. But the quantity field should still function normally for products and product listings of other categories (to be created in future). Is there a way to do this?

Thank you =)