You thought it right. The White paper was written after the fork that implemented those changes. I'm not sure what stonehedge calls "lightweight", so i'd also appreciate if he explained what he means by that.
The whitepaper is quite detailed for a whitepaper. Keep in mind this is not an academic article, but a business one, so yes, he has to keep it simple so business people (i.e. investors) can understand it. If you need more detailed explanations of the science and technology behind the implementation, i am sure Mr. Spread will be glad to provide it, but that is not the point of a whitepaper.
Whether I read it as an investor or as an IT professional, it still doesn't actually mention many plans of features for the coin.
I really like the idea of decentralising mining. I would love to see this coin work. Mr Spread has proven himself to know what he is doing. Having said that, he hasn't shared much of those plans with the public yet.
On a separate note I tried to mine some Spreadcoins over the last two days but the provided X11 miner only gets 1MH out of a 290x and network hashrate is over 2GH. I'd be interested to see whether by removing pools this coin has simply created a solo mine arms race. 2GHps of X11 is a lot of GPUs