Just to clarify a few points:
One, anyone who wishes to start a bookselling business can set up with Createspace to buy books directly. If you look in your settings under channels, one of them is Createspace Direct. If you are genuinely that concerned about it, turn off that option. Problem solved.
Two, yes, expanded distribution sales will always appear in lumps because they are sales to RETAILERS not CONSUMERS. If B&N buys ten copies of your book to keep in inventory, those sales will be recorded when B&N buys the books. It might take them 10 months to sell those books. But it doesn't matter. You get paid when the retailer buys the book.
Three, no, trade publishers do not have the same set-up with Amazon that we do. They have a traditional wholesale arrangement. Amazon pays X for the books and then sells them for whatever they want. So SImon and Schuster doesn't particularly care if Jane Doe the 3rd party seller undercuts Amazon's price. They got their money from Amazon already for the wholesale books.
Four, indies tend to set their paperback prices way too low anyway. Set your paperback prices at normal retail rates and you can make a decent profit regardless of who sells it. If your margins are so low that you can't make money on third-party or expanded distro sales, you aren't pricing correctly. The thing is: print sales are driven by the appearance of sales. Set your prices at normal retail and then PRAY the retailers place your book on sale. Because your royalty on PRINT is based on your retail price, not the price the book sells for.