@ Andrew I have some asnwers for you
Impalers roll 2d6 on their hit and run check, so can score a 9.
Shadowfields are identical to holofields, and in MMS they offer no protection against NC. In BFG:R plaxor has it so that NC can reroll their scatter die if locked on, so presumably to counter this holo/shadow fields will get the vs. lance save against them, or take plaxors approach and allow them to force a reroll of direct hits.
Leech torpedo's should not cause damage IMO, because that makes normal torpedoes superfluous.
If we are using MMS 1.9b presumably we will make DE movement copy paste of CE and craftworld eldar.