How difficult should it be to turn over by hand??

3 times max after it's out of the factory.

If you have to replace the rod bolts, you should have the crank bore on the rod refinished as the bolts locate the cap and the new bolts will locate the cap differently. It will need to be re-machined when you change the bolts...

Here's a link to some replacement bolts:

http://www.manciniracing.com/rodbolts.html

Not with ARP bolts they are not torque to yield.