Lou: So do you follow the same logic in regards to buying a game say at WalMart or Amazon or Gamestop.
First, you appear to be misunderstanding the type of support required. If, for example, you can't download a product from a store, you don't submit a support request to the developer. You submit it to the store. It's their problem. If the game constantly crashes or displays strange behavior, you don't contact the store, you contact the developer and in the event they can't solve it and a refund is subsequently required then you contact the store.
This is true of all digital distributors, despite the BS no refund policy they try to get away with.
The same is true of retail. If there's a problem with the media (which is something the store is responsible for) they handle it.
Now to your specific examples (of which only one applies to me):
Amazon have a fucking good support system and have helped many a time when there has been an issue with a product, be it a DVD or PC game, which can be attributed to them. As I can't buy PC games in B&M stores here, I couldn't tell you how they'd handle such an issue. Although most likely, they'd replace the game with a new copy -- as they do for console games.
So to answer your question, when purchasing PC games digitally, I apply the same logic to every single store I use. I don't buy full games from Steam, for example due, in part, to their shite support (which is still miles better than the support here). I buy games full price from GamersGate as, so far, their support and willingness to offer refunds when an issue cannot be resolved, is excellent.