Rule 2 is a good idea, but realistically, being too strict about the length ofanswers you expect is unlikely to motivate people to be wordier. I know that with some of my friends, if the one-word answer weren't deemed good enough, they'd just not respond at all anymore. People have different reasons for the ways they communicate, and in the case of aforementioned friends, they are just not very good at talking without a really good prompt. If someone talks to me about a topic I don't know enough about to contribute anything useful, my answers are likely going to be one-worded as well - regardless of how interesting the topic is to me.
I disagree with rule 7. One of the benefits in written communication
is the ability to take a step back and think things through (or just wait until I'm in the right mood) before replying. I do not make good choices or even remember things correctly when put on the spot, so if someone expects me to answer them without delay, they might just as well get me drunk first, as my brain's helpfulness will roughly be the same.

I am fine with rule 8. I never leave voice messages myself, and rarely get one from other people. It's more common here to just call again after a while.
Rule 9 adresses one of my greatest annoyances on the internet. Happens a lot, unfortunately, even if I list each point neatly with a number and bolding. No idea why it happens so often or how to prevent it.
I don't see the reasoning behind rule 12. Sure, if there is an active chat going with five or six people, and two of them randomly start ignoring everything around them and just talking between themselves as if nobody else existed, that is rude. But in the group chats I am a part of, there are a lot of dead hours inbetween where nobody really has anything to say or is even online. If Two members happen to have a good topic and both be online during such a time, I don't see a problem in them discussing it one-on-one until somebody else comes in and might also find the topic interesting and add to it.
13) Personally, I prefer both sending and receiving
any kind of news via text, mostly due to the problems I explained under rule 7.
15) I guess, technically, this is true. However, if someone takes their time with a response, it's not always necessarily because they don't have time. It might be because they need to discuss with a third party, seek out some information, think of a better way to phrase their response, calm down, or any number of other reasons that don't effect their snapchatting.