would a three-view multiview drawiing be enough to communicate the size, shape, and features of any object?

Answer 1

Not always. Picture a cube with a spherical hole in the center....with a three-view multiview only (i.e. no cutaway view) you would only know there is a hole there with hidden lines which you can't dimension. Also, think about a crumpled up ball of paper. This would require several cutaway view which lay over each other. Hope this helps.

Answer 2

In most cases, yes.
But even with experience in reading this type of mechanical drawing, a nice 3/4 view is always very helpful in conventionalizing the final piece.