Yes I think Pikemen usually deal out SPECIALIST damage.
To find a unit's speed find its object definition and look for 'LocomotorSet'. Then change the 'Speed' value in your mod.
Unit cost is set by 'BuildCost'
Damage is set by the Weapon in question e.g. for Gandalf's main weapon in vanilla the GondorGandfalf object in gandalf.ini specifies his main weapon as 'GandalfSword'. Find this weapon in weapon.ini and then change the 'Damage' value in the DamageNugget in your mod.Go to the full post