Even if the pistons arent seized you still wont turn it by hand without some form of leverage. If the rings and bores are in great shape with no rust there is still drag of the rings sliding along the cylinder wall.
If you have no balancer and no flywheel I would put the balancer bolt in(if you have it) stacked up with washers if necessary and turn the engine over with a breaker bar.
As for the pistons going to the deck, its probably normal. Im not sure about the 5.0, but some sit down a little below the deck, some are even, some stick up a tiny bit. Remember, theres normally a headgasket there that makes clearance between the piston top and the head even on a zero deck setup.