You have gotten some good advice. I loosen the springs up almost to the point of no tension. just enough to get some brakes in reverse when parked. Since there is a foot brake for parking the springs are not totally necessary. It makes the machine so much easier to drive and with more control. I have an old Hustler with no springs and it is easy to drive without the springs, but it just might roll away on a hill without a chock block. I don't have a parking brake in it.

I have seen a modified left stick. The lever is attached to the left stick and it wraps out in front of the driver over to the left. The vehicle is then driven more like a bobcat with the arms to the sides of the operator.