Get yourself some optimum no rinse. It is a rinseless wash. Use that to wash your car. It will save you a ton of time. ONR has water softening capabilities
When i did it i had on jack stands as high as i needed to get under confortable. If leveled it will drain some but it won't be that much of a difference.
Our water is pretty hard -- we drink it with a fork and knife. Don't wash a car in the sun and get it dry using an Absorber as soon as you can. No issues
Seafoam is a bit harsh in my opinion. I would install the catch can, clean the throttle body and run TCW3 in the fuel.
Have not heard of that - is it off I-10?