#4 The instructions say to turn off the electrowall after each use. How does this work if you have the vacuum unit on automatic?
The electric wall is the little box that tells the unit it cannot go to the place where you put the little box. There's an on / off switch on the little unit.
#5 How effective is this vaccuum for sand on a tile floor?
It has two modes: Normal and Turbo; Since normal mode is very effective, turbo mode mut be enough for your requirements. Obviously, battery wiil be discharged more quickly.
#6 Ili A9 brings its own device for the water tank to map?
No. This version does not use water for cleaning. When it comes to mapping, it is because it has the functionality of registering your location (like a map). It is an excellent product.