Yes or a heavy duty outdoor extension cord.
The motion function on this projector can be disabled.
They come with ground stakes but you could virtually do anything you wanted with them. I'm sure they could easily be mounted anywhere you like. The stakes are optional, you do not have to put them on. I would say yes you could easily Mount them to shine down.
Very efficient. I use multiple during Halloween & Christmas. All sides of my house are lit up!! There is virtually no noticeable difference in my utility bill.