I'm able to list products by categories, how do you list all product on one page disregarding categories?
There are two ways... the simplest is to enable the menu item for /products that does this, but my recommendation would be to use Views to make a View that shows all product nodes. You'll have more flexibility over fields included, number per page, etc. with Views.
If you have Views, the product module puts a default View at that location that you can edit.
Awesome, didn't know that happened. 
Is there some way to use this Default view to change the way other product categories are generated? It would be really awesome if we can use Views to set how generated categories should look and still keep automatic generation of menus. Maybe I missed something but right now the only way I see to use Views with Ubercart is to make new view type for every category (I know about arguments, but I still feel like there just must be something better).

