disable billing address during checkout?

Hi,

If you don't have a weight in your products and that the "force shipping regardless of weight" setting is turend off in the Hikashop configuration, you won't get the shipping address interface.
If you want to remove completely the address view from the checkout, you can do that with the "checkout workflow" setting of the HikaShop configuration.
If you want to disable the address fields on the user registration, you can turn off the "ask address on registration" setting of the HikaShop configuration.

So there are different solutions based on what you exactly mean by "disable billing address during checkout".