There are no absolute rules on how long a pause should be. As Andrew commented "it appears there may be a misunderstanding about pausing and intonation".
- When we read a book to ourselves we may or may not make long or shot pauses, intentionally or not we might not even notice ourselves pausing.
- When we read aloud for someone (especially if that someone is listening) we need to show the pause so that the listener can understand. Whether we do it by applying a short pause or a long one or by changing our intonation is personal, as a matter of fact, generally, it is done unintentionally. (Try to read this sentence aloud as if someone is listening)
You say that a "period and colon" is followed by approximately two seconds of wait time. Okay.
- Hello. How are you? How are your parents? - If you read this naturally (as most will) you will notice that there is almost no pause after the periods. And if there is then it's less than a second long.
Surely you can intentionally place a 2-seconds-long pause in there or wait as long as you like. You can shadow your intonation if you want. We aren't robots that have rules they obey!
- The weather was... em... what was it like? Oh, yeh, it was raining!
In this sentence you can add very long pauses if you want to show that the person was trying to remember. You can pause for more than 2 or 3 seconds in the first part and in the second part too. You will, probably, intentionally show emotions and intonation.
Conclusion: Opinion on how long a pause should be is personal.
Everything depends on the person, text, and his ability to read aloud
or/and speak. Pause and intonation are different things.