There are times when fandom_grammar is not enough for me and my passion for punctuation explodes from my face (beware projectile commas). There are also times when I read a few fics in a row that have no conception of how to punctuate for pauses, and that vexes me.

So, today you all are suffering through a lesson on punctuation for pauses.

Lesson 1: Periods end sentences.
Periods signal the end of a complete sentence. A complete sentence—for those who need the reminder—is a complete thought with a subject and a predicate, or (boiling it down even more) a noun/pronoun and a verb. Complete sentences include:

Daniel kind of ran.

Sirius transfigures the table and falls asleep.

Notice that each complete thought ends with the proper terminal punctuation that signifies the end of the sentence.

These are NOT complete sentences:

Daniel kind of. Ran.

Sirius transfigures the table and. Falls asleep?

These are not complete sentences because Daniel kind of doesn't have a verb; it's not a complete thought even. A complete sentence should tell you what Daniel is doing. Sirius transfigures the table and is also not a complete sentence because it isn't a complete thought. Sirius transfigures isn't even a complete sentence because "transfigure" is a transitive verb, which means that it needs an object. In this sentence the object is the table. So a complete sentence is Sirius transfigures the table. However, and is a conjunction, which means that it joins two thoughts together. Unless your point is to prompt further explanation with the sarcastic "And?" you cannot end a sentence with and.

Lesson 2: How to pause.
There are two ways to punctuate a pause in the middle of the sentence—use an ellipsis or use an em dash.

Daniel kind of . . . ran.

This example is showing a hesitation in defining the way Daniel is moving. The narrator is struggling to find the right word and finally settles. That hesitation is shown through the ellipsis—a piece of punctuation that doesn't end a sentence but conveys a pause.

Sirius transfigures the table and . . . falls asleep?

Sirius transfigures the table and—falls asleep?

The ellipsis works in this sentence as well, but I would encourage the use an an em dash here. Why, you may ask. Because an em dash signals a change in direction. An ellipsis is very specifically used to designate an omission or pause, whereas an em dash symbolizes a break in thought. Originally this sentence would probably have been a statement and ended in a period, however, when the narrator saw Sirius fall asleep, he was surprised and the end of his sentence became a question. Since there was a change in direction in the middle of the sentence, an em dash is more likely to be the appropriate punctuation here.

In Summary
Punctuation is efficient. It's short-hand for the author's intended meaning. And while Daniel kind of. Runs. does get across the intended pause, it ignores the fact that there is a piece of punctuation that would convey this inflection, and it misuses the period, signaling an end of a sentence that isn't a sentence.

In short: Don't abuse punctuation!

Also, I provided a very nice write up on punctuating pauses at fandom_grammar last November.