I'm not sure why you say it's a strawman? The whitepaper[1] says that an ask order on the storage market is just (space, price) -- no mention of the cost to retrieve the data. Similarly, the storage market protocol (Figure 11) doesn't mention losing stake for failing to provide the data on demand (it only mentions losing stake for failing to post proofs).
I admit that the concept of retrieval miners makes no sense to me since it seems like they would have to be the same as the storage miners. It is worrying that the whitepaper says "we must assume that there is always one honest Retrieval Miner"; you can't assume honesty without incentives.
In general, I don't take the Filecoin whitepaper too literally. There are a lot of aspects of it that will probably have to be changed. I think the Filecoin ICO (which I didn't participate in BTW) is more of a vote of confidence on the team, not any specific protocol.
(Also, for step 3 I think proofs of storage are supposed to be calculated continuously, not once. So you'd be constantly reading data from S3.)