There are a couple of things that can be done or checked at least on your machine.
When the stick overlap that is generally a sign of some where in the square mounting blocks that the drive levers bolt to or in the bolts that act as "stops" for the blocks when you swing the drive levers in. You can replace the bolt which usually makes a pretty big difference or replace the blocks with can make a big difference or use a "strong arm" adjustment to bend the drive levers back out a little bit. The blocks are generally not a real big wear item but they can be. I'd focus on the bolts and drive levers.
First you must determine if the "pull" is normal. The only "pull" should be with the drive levers at full ground speed. The mower should drive straight at all speeds until you hit full forward or full reverse.
When a machine pulls to one side or another it's most often an issue with tire pressure or tire circumference. First check your tire pressure and then give the machine a try. Next measure around the tire circumference and make sure each tire is with in 1/2" of the other. If they are not air up the smaller of the two. Once that all checks out you then need to determine if the drive levers have "slipped". The drive lever is mounted in slotted holes so you can adjust them forward or back for operator comfort. Once in a while the hardware can become loose and the adjustment will shift. To check this simply swing the drive levers in and make sure they line up. If they don't then loosen the mounting bolts and make the proper adjustment.
If you notice the machine pulls to the right when under load or going up hills you may want to look at the pump drive belt and the pivot for the spring loaded idler.
If all of these check out okay I'd take the unit to the dealer for inspection.