I beg to differ on one or two points. Because most people do not have the programs that printers use, many, if not most printers, will ask for a print ready pdf that includes bleed and crop (cut) marks. They have programs they can import the pdf into and work with files that way, as needed. Most people cannot afford the Adobe programs but almost all design programs available can export files to pdf. Ask before you send a native file from whatever program you're using; they may not be able to work with your files (i.e. we don't accept MS Publisher files AT ALL!).
Any reputable printer will insist you see and approve a proof before they'll go ahead and print your file. I work in a print shop and we send digital proofs out on 98% of orders. On some orders, we insist the customer see a printed proof and on any order, a customer is more than welcome to ask for a printed proof.
You are correct, though, about colour matching to something you've had printed elsewhere; it's next to impossible. Heck, there are times we have issues matching colour to something we printed previously because, believe it or not, even the weather can affect how the colours come out from one time to the next.