Hi,
If you have a lot of products to configure, the best is to generate a CSV with the data and import everything in one go. You can also do that with the discounts in the hikashop_discount table via your PHPMyAdmin.
Regarding the product selector, I don't see a valid reason to add a published/unpublished filter. In that case, why not a filter on the quantity, one on the prices, one on the characteristics, etc. In the end it's a matter of balance between what's really essential to most people and not cluttering the interface with too many things.
So I understand what you're saying and in your case it might make sense, but I hope you can also understand our point of view on that.