How to disable Commerce, but still have the module for later use? So I have a client that needs the ability to have a store without the actual eCommerce right now. Later, the client will enable the checkout/payment features of Commerce and run it like normal. So basically:

1) Client still needs the catalog, create products, show products and pricing, etc.
2) A customer can't actually purchase anything, there is no cart, you can't checkout, etc.

Is it as easy as disabling the cart submodule? Or would hiding the add to cart buttons and requiring higher levels of auth to view /cart? I've thought of both but don't know what would be foolproof.

I know I can just create custom content types that will do the same thing as creating products, but I know in about six months or so they want to turn the ecommerce on and I don't really want to have to convert everything to products and do all the work then. I'd like to just create the products normally right now and just flip a switch later.
Drupal modules in general can be disabled and uninstalled without major problems. Last version of Drupal Commerce (1.5) includes 20 modules, and some of them are totally independent. You definitely can disable Cart and Cart UI modules without disabling others such as the Product and Tax modules.

However, there is an important bug in Drupal Commerce relevant to re-enabling modules that it's still not fixed. See http://drupal.org/node/1361562