Is there anything wrong with shooting 30"-31" cedar shafts??? If tuned to the bow is this too long of an arrow to be used for hunting?? Does the long length retard penetration due to excess paradox.  Hill has been quoted as saying  "It is better for one to shoot a 28" shaft" "easier to ballance and easier to find heavy enough spine."
Hopefully he ment for "his" bows {80#'s}

I don't think you would have excess paradox with a longer shaft.  You would if you just took two identical shafts and cut one longer than the other.  However, then one or the other of them would not be tuned for your bow.

If you take two shafts, both of which are tuned for your bow, one longer than the other, I believe the longer one will actually have less paradox than the shorter one.  For both the shorter and the longer shafts to be tuned for your bow, the shorter shaft would necessarily have to have a weaker spine than the longer shaft, and therefore would have more paradox than the longer shaft.  Or possibly the weaker spine of the shorter shaft would be offset by the extra length of the longer shaft, so they would both end up with the same dynamic spine in order to be tuned for your bow, so possibly the paradox would be the same, I'm not sure.

There may be other reasons for keeping the shafts as short as possible, but excess paradox on the longer shaft is not one of them.

Nope.  To be properly tuned to your bow, the longer shaft will need a little heavier spine as McDave notes.  Arrow flex (Not paradox.  That's a totally different concept.) at impact is what retards penetration.  Without testing, it's difficult to say which arrow would flex more, the longer, stiffer one, or the shorter, less stiff one.  Regardless, the difference is probably insignificant.

Ok, so would one be alright hunting with 31" cedars or would one be better off with one of the synthetics?

You may run into spine issues with the longer shaft and depending on you set up. To make a 31" BOP arrow you will need a perfect 32" shaft-a synthetic, or footed wood shaft may be the answer for you.

I like the new CX Heritage and Beman MFX's and all, but sometimes I want to just pull out the wood arrows. Thanks Gents