As said it sure sounds like a batt/cables/starter issue & hard to tell which as the symptoms are the same between the three. Were all the points of contact for the new cables cleaned including starter to block/block to body/body to batt neg post? If you have another vehicle I'd sub in the batt then the starter to confirm or eliminate them if the cable connections are good. Yes if you have control of the idle mixture screws you're good on the throttle opening. Keep us posted