Racetrack will be the washboard that gets you. Mix of sand and gravel surface. Took me 3 hrs in, 2 hrs out. Don't forget to bring an old tea kettle. I have 4WD but 2WD s/b fine with due caution and moderate skill.
Titus is mostly hard packed mud to give a very solid surface. Do not go if it has been raining or could rain. The approach to red pass will be deep mud. I barely made it in 4WD. The end is in a stream bed (slight down hill) with loose gravel but decent 2WD s/b fine.
20mule team canyon? Do you mean Borax works? Any vehicle can make this short easy drive to see the legacy equipment. Or something else?
Most of the road descriptions are overly cautious and the actual drive will be easier than expected. Of course conditions can vary. Always allow more time than you expect. Carry extra food and water.