Hi,
In your custom address fields, you have a setting "type of address". You can select "shipping" in it.
And in the HikaShop configuration, you can turn off the "force shipping regardless of weight" setting.
That way, for products without a weight, the shipping address won't be asked and the shipping method also won't be asked to the customers.
Also, in the HikaShop configuration, you can set the "type" setting of the "address" area to "shipping" so it will either ask for the shipping address or nothing if the products in the cart have no weight.