Why would Amazon want to bear the cost of people using their store as a free product billboard, or using their warehouses as cheap transient storage space, while trying to push customers to actually make their purchases elsewhere?
I'm not sure how this can be considered 'regulation' of the market, however -- to the contrary, it signifies that Amazon itself is sensitive to price pressure coming from competing distribution channels.
That’s clearly in violation of antitrust laws.
Every bit of what you're describing is the way retail distribution works across the industry in general. Amazon isn't doing anything out of the ordinary in any way.