Leak Down Test On My New 418 Need Help?

The question should be where is the leakage going? you didn't specify that this was all into the crankcase . You could have 4 bad valves at 5/6% and then the ring leakage might all average out to say 5 or 6%, which at 150 miles doesn't sound catastrophic anymore.
So perhaps you have multiple problems, at least one of which might settle down with more miles.
The 2-4 could be a head gasket as could 1 and 7,puking pressure into the CC, as far as that goes, and that could also be the contributing factor to the oil consumption.
So, the point is, your LD test is telling us something, but without qualifiers it is almost impossible to interpret

AS to the rocking, the piston crowns are quite a bit smaller than the skirts and so rocking is normal. You should see pistons in outboard marine engines, they rattle around up there.