Hi,

As I said before, I completely understand your choices, which are completely viable. You never know, maybe fago you will be crunched by a tank tomorrow, if it's the case, who will develop rules module ?

The fact to provide minimum function in ubercart core and provide the possibilities to extend them with third party module is probably the best choice for usability and extensibility, but this is the choice that bring the most work for you

But be carefull, by providing too much out of the box feature, it finally could be more difficult to personalize ubercart than directly provide an integration with a less "out of the box" module, but more powerfull, and the product listing is a good example for that.

Imagine that an user, that was firstly happy with the core listing product now want something that is not possible with it, and it can be a simple thing, like adding the product SKU in the listing or providing an AJAX pagination.

He will have 2 solutions : coding ajax pagination in a custom module for the default product listing, or reproduct the listing with views, that already provide ajax pagination. Using views will be more simple for him but will involve to create the view, theme it as the product listing he had etc.... Finally, it was more simple to directly create the listing with view, and just add the SKU column by adding it under the field section of views.