Craig, I enjoy reading your ideas. I really do.
This post is very interesting to me because I am creating websites as a business and one of my main talents has always been expressing ideas through the written word. (Not saying that to brag, just stating what I and others have observed about me since I was a child.)
The second paragraph in your last post makes me think of an idea I just read on the E-Myth website. It was talking about knowing who your "most probable customer" is, and one way to do that is to find out what personality traits your existing customers have. For example, does your business attract people who are more outgoing or introverted, more creative or technical? (It seemed this could also apply to the "personality" of the business they are in.) The idea was that if you know what type of person or business is attracted to your company currently, you can focus on attracting more of the same, and will probably be more successful at it than with generalized advertising.
This is something I think about when working on ideas for a website, although not in a formal way. I try to envision the typical customer (I ask potential clients what their typical customer is like) and think about what will appeal to that person, in both the design and copy.
I think being able to "hear" voice tone in writing depends largely on the writing itself being of good quality.
As far as standards for language...well, there are grammar, spelling, and punctuation rules! I think one reason there aren`t strict standards for language like there are for coding (for example) is that language is so much more flexible. If I want to make a blue background on a web page, there is one (maybe two) standards-compliant way to do it. If I want tell a funny story about something my cat did, I could come up with thousands of variations that would all be correct, and many that would be considered an excellent telling of the story.
Language is more of an artistic medium, but the rendering of a website is a technical issue. I think that may be the key point. You can only go so far with creating "standards" for art.

Okay, I can go along with the idea that we could come up with guidelines for making a website conversational, and I think it would a useful thing to do.
1. You said to have links to different topics that a visitor might be interested in as part of the text. I see that this serves two purposes. One, it allows the visitor to choose which topics he or she is interested in (which is good on a website that might cover several topics), and two, if the website owner tracks clicks, it allows him or her to see which topics visitors are most interested in.
2. I agree that having non-rhetorical questions is not necessarily the way to go to make it conversational. I think it works for some sites--for example, on a travel site it might ask "where would you like to go?" and have a list of destinations for you to click and get more information. I think rhetorical questions can also be used effectively to get people thinking, especially if you want to make them more aware of the problem they have that you can solve.
3. Interactive features add to the conversation aspect of a site. The more social or entertainment-based sites can use polls well. Here you are asking what someone thinks, they reply by clicking their choice, and then they see what everyone else thought, too. I`ve usually found something satisfying about taking a poll, especially when there are many replies already. Then you sort of measure yourself against the crowd, and suddenly looking at this website isn`t something that you are personally doing--it`s a group activity. It`s social. I think many websites could benefit by beefing up the social aspect of their site--by making the visitor feel like it`s not just him or her having an interaction with a company, but that many people have done this and are doing it, and it`s a good thing.
Craig, I would like to use this topic as the topic of my next Website Success Tips newsletter, which will go out in about two weeks. I would credit you with coming up with the idea and credit your contributions. I can even give you an "about me" paragraph at the bottom. Is it okay with you that I use these ideas for my newsletter?