displaying short discription in the category view

In the hikashop options of your products listing menu/module, you need to select the item box layout "image and description". Then, in the description of your products, you can add a read more tag. Only the text before the read more tag of the product description will be displayed. The full description will then be displayed on the product page.

Yes.

That's not the hikashop options of your menu/module. That's the options of the Display tab of the config.

You can find the hikashop options of your menu/module via the menu Display->Content menu/module in HikaShop.