The couple of times I've tried SoftwareSerial and ServoTimer2 have worked together fine.
The only thing you need to be aware of is that ServoTimer2.write() takes a pulse length in microseconds not a 0-180 angle, so it is equivalent to Servo.writeMicroseconds() not Servo.write(). If you try doing write(90) nothing will happen because 90 microseconds is below the minimum.
Steve