The fix for the hard shift into reverse is a updated solenoid pack. This is the electrical part of the transmission and that transmission has had a problem with them from day one.
The shifting into 2nd and 4th is a bit different. What happens is the band servo bores in the transmission case get a small groove in them and case the servos to hang up during application. In this case, the fix is to remove the transmission, and install bronze bushings in each servo bore.
Before you get to that level though, I would have a dealership replace the solenoid pack and reprogram the engine / transmission control computer to the latest software and redrive the vehicle. At that low of a mileage, the shifting may be a software issue.
Mercury Technician
Ford Lincoln Mercury Senior Master Technician