ugh...just lost my post....
to recap in less words

plants get crushed by the snake, need light that affects your heat levels, and can't be disinfected when pooped on.
good silk plants (fake) look real, need no care, and can be pulled out and cleaned easily.

soil...you need to use soil that is free of bugs and other nasties. many people use Coco bedding, which is a lot like soil
you don't want your snake to be on damp substrate so if using soil-like stuff be careful about how much you mist.
I like cypress mulch....easy to clean, holds humidity, and dries/drains really well.