I'm not sure about the reliability of that German Article. Even besides the Sea Dagger misunderstanding, do you really think the Dutch will not lose happiness when they trade away their luxuries? I mean, that's a pretty insane ability, it means there is never a reason not to trade away luxuries.
I also doubt about Polders ''creating land''. Sure, it has happenend (http://en.wikipedia.org/wiki/Flevoland). Especially marshes and lakes. But the only way to implement is on marshes. It's impossible to get a workboat on a lake tile and if it applies to coastal tiles it would be hugely overpowered. I'm not even so sure about the tullips to be honest, seems a bit odd to me.
I also doubt about Polders ''creating land''. Sure, it has happenend (http://en.wikipedia.org/wiki/Flevoland). Especially marshes and lakes. But the only way to implement is on marshes. It's impossible to get a workboat on a lake tile and if it applies to coastal tiles it would be hugely overpowered. I'm not even so sure about the tullips to be honest, seems a bit odd to me.