Padding for Inline Elements

It is claimed in the book that an inline element has complete padding properties but no margin-top/button properties, only margin-left/right properties.

My first question is, where can I find this as an official statement?

You won't, because it isn't quite true. In the box model it says that for margin-top and margin-bottom:

These properties have no effect on non-replaced inline elements.

But "no effect" does not mean that the properties don't exist. Specifically, they do exist for the purposes of inheritance. Consider this example:

p { border:1px solid red }
i { vertical-align:top; }
span { margin-top: 20px; margin-bottom: 20px;  }
b { display:inline-block; }
.two { margin:inherit;  }

<p><i>Hello</i> <span>World <b class="one">my good friend</b></span></p>
<p><i>Hello</i> <span>World <b class="two">my good friend</b></span></p>

We can see that the b element with class "two" inherits the margin top and bottom properties of the inline, non-replaced span element, and since that b element is inline-block, the margin-top and bottom do cause a layout difference. That would be impossible if the margin-top and bottom properties did not exist on the span.