I decided to add some Water Wetter to my radiator, when I noticed that that overfill tank is about an inch above the max line. I ended up just using a turkey baster to siphon some fluid out of the radiator itself so I can add the wetter, but the overfill tank is designed so you can't get in there to siphon out. Am I safe with this filled above the max line, or any other way to drain some other than getting under and finding the drain valve?

 

You are safe above the max line. The max line is more of a guideline. There is no damage to your car if you have to much coolant, all that will happen is when the car heats up it will blow off the extra coolant.