I always drive with a spare transmission, although it does not have a reverse gear, I cheaped out and figured that I do not drive in reverse all that often.
I wouldn't trust anything that isn't labled properly. After all you need different blinker fluid for the tail lights. That one is like shampoo and conditioner in 1. Better if it is separate.
I prefer the synthetic stuff, I know the extra cost is hard to swallow.But it does make a huge difference when you forget to brushed the snow off them.