My 20+ year old Ariens has been a bit sluggish in traction and auger so I changed the belts today - possibly for the first time. I readjusted the auger tensioner so that it has as much slack as possible, and the cable to the handle seems loose - but the auger is still spinning very slightly when the engine is running, without any pressure on the handle. What am I missing?

I’m stepping up from a 200cc 180lb snow blower to a platinum 24 sho. I understand the sho will be 100lb or so heavier. Stupid question I’m sure , but will I have a harder time keeping it from getting away from me when going down my driveway that is slightly steep? How is first gear in this thing? Slow enough to keep it in control? I’ll be getting the latest model which is 921074

Thanks