Try to get a picture of the cam alignment as well as the crank, it's normal for the crank to be off a little bit when the cams are aligned due to cam chain stretch, but this will be minimal, as in the pics below. My 2011 with 19,000 km, original chain.
So the tensioner on your bike is a manual (externally adjustable) unit? Too much tension is never a good thing, but unless it's is ridiculously tight it shouldn't create any issues. Please post pictures of the gap you are referring to since I'm a bit confused.
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