Good write up. I did a similar write up last month
My only comment is that if you remove the oil filler cap and filter before you drain the oil, it will help the oil drain faster by allowing air to displace the oil as it is draining.
The other comment is about driving it on ramps. Putting the car at an angle will prevent some of the oil from draining. You want to make sure the car is level on the ground and all the oil is completely drained before putting the plug back on. I had to jack the car up because I'm to big to fit under the car and reach the drain plug but I did put it on level ground before reinstalling the drani plug and some more oil came out. I like that drain valve idea. I'm going to order one of those for all my cars.
Here is a link to my write up:
07 Deep GXP -
Foot Well lights, side marker turn signal, trunk spring, Antenna Delete, Retractable License plate, Clear Turn signals, Painted Calipers+decals
My solstice Site with HowTo Articles- http://www.cherod.com/solstice