Some of your headaches do come from the policies of manufacturers while some come from lazy dealers.
The guys that sell out of their homes are often "trunk slammers" that have no investment in the company. Beware.
Some manufacturers and/or their distributors/importers are easy to work with. YBA, Kimber, Spendor, Parasound, and Von Shweikert come to mind. If you want to demo a product your dealer doesn't happen to have, these companies often have no problem letting the dealer borrow stuff. It does involve the dealer taking time and money to make it happen.
Many manufacturers also hessitate to tell the consumer much about their interactions with dealers to protect the dealers. When orders fall through the cracks, items are backordered, or billing issues arise dealers have to make some sort of excuse to the customer. If a manufacturer contradicts their dealer the dealer has egg on his face.
Manufacturers first priority is selling product.
Dealers are what facilitates manufacturers selling more product.
Dealers have to make money to stay in business.
There is a symbiotic relationship there.
Good manufacturers and good dealers still look out for the customer in hopes of repeat business if and only if the relationship with said customer allows both to make some proffit. If a customer wants a product at the same price it cost the dealer to get it to his door, the dealer has no reason to nurture the relationship. Same can be said of the relationship between manufacturers and dealers. If it is no longer profitable for one or the other what is the point? Sony and Yamaha are two manufacturers that most dealers can probably live without. Pain-in-the-ass dealers are often dropped by manufacturers too.