Concerning your lakes, I'm not a expert, but I think there are many explanations. A natural basin where all the nearby rivers are pouring is the best explanation, and this basin could have been the result of an now-disappeared icy cap, erosion of a soil more fragile than the surrounding lands, and probably other reasons (the opening of a rift is creating a series of long lakes, like in eastern africa).
This other version of the coasts is not that bad, but I indeed prefer the first one.