Catalog mode On or Off for invoicing?

-- HikaShop version -- : newest
-- Joomla version -- : newest

I'mdrivin my site in catalog mode. No e-shop.

Anyhow I want my client to make the billing through HikaShop instead of using third party software or extension.

My question is:

Can the administrator of the site create invoices and use selling functions without activating the shop?

Then,

IF I deactivate catalog mode I understand I enter in Cart Mode.

But, I don't want my registered users to buy products, just to see them and call the administrator of the website (and the business) to ask for a person-to-person sale as each product is very unique and requires professional-to-professional negotiation.

So, could the administrator after the negotiation open a cart for that client and add the products, emit the invoice and close the sale in a way that the registered user does not even notice the cart is there?

I want my users to get access to invoices but not much more, no cart, no delivery emails no nothing else.

Is it feasible to use HikaShop this way?