Do you really requirement to own a fracture between wall/floors tiles? ...
Answers: No but drying time will be increased considerably especially with full-size format tiles.
Edit, The joint could be reduced to the minimum that can be achieve with engineering tolerances of the tiles whilst still providing a sealed surface of the finished wall. Expansion/movement joint are are usually created at edges/corners.
yes otherwise how will you grout them,
grout is the paste between the tiles,