Set up your IK chain to go from the end to the bone BEFORE the center bone (or maybe the 2nd one in, depending on how many bones you used for each arm,) that way the center can still be free to move the model as a whole and not be constrained to all 5 (or with the octopus 8!) IK chains. Nice modeling... I don't see why you bother with online $#! if you can do that yourself. :D