Phono preamp/turntable connection question.

Tone arm to preamp. If that connection gets messed with, nothing you can do about it downstream.
FWIW, cartridges are a balanced source so you can run a balanced connection between the tone arm and preamp. Balanced lines are more neutral, so this connection will deliver the signal better and the cable isn't (or doesn't have to be) expensive.

Agreed.  Use the best cable from table to phono stage.  You are sending much lower level signal and as atmasphere said above, if that gets messed up in any way there is nothing you can do to fix the signal.

+1 atmasphere

My experience has told me to use the best cable from the SUT to the phono ~ since the SUT is doing wonderful things with the signal, keep it as short as possible.  If no SUT, then use your best cable from TT to phono.

Yes.  But you should experiment, besides you may not know which one is 'best' cable.

Tonearm to phono stage is the most critical to proper cable selection. You want the lowest capacitance cable as possible and good shielding with high output impedance moving magnet cartridges. Moving coil cartridges with significantly lower output impedance are much less prone to signal loss from capacitive reactance in the cable, but much more prone to interference, so shielding is a bigger issue there. Line level output impedance is usually low enough to overcome capacitive reactance issues and strong enough for good s:n, but that is a variable that changes from one environment to another. 

Atmosphere....just wondering if balanced cable is an "upgrade" if no other component in the system is balanced as well.

You have them, experiment. Put them where they sound best to you.

stringreen

... just wondering if balanced cable is an "upgrade" if no other component in the system is balanced as well.

A "balanced" cable that isn't connected to a balanced circuit really isn't really functioning as a "balanced" cable at all.

One recommendation for tonearm to phono stage, as a cable with very low capacitance, is Blue Jeans LC-1 (Belden). Highly affordable and is among the lowest capacitance at 12.2 pF/foot. I use them for both MM and MC cartridges. Great value!

just wondering if balanced cable is an "upgrade" if no other component in the system is balanced as well.

If you have an SUT, then that can convert from balanced to single-ended no worries. Otherwise, no benefit.