Certain persons have taken to posting their own unique and fringe beliefs and interpretations, and have come up with a label for them in order to present them as if they weren't personal theories. This site is about the beliefs of Christian groups around the world, not personal ideas. I think this person is misappropriating a valid label for their own ideas, ideas which do not reflect the beliefs of the people the name originally applied to. Furthermore I'm quite certain that no one else in the world follows this persons' way of interpreting the Bible. Their beliefs cannot be compared to other denominations and it is very unclear whether they actually even believe in a god at all. I've had enough of reading their nonsense filled posts and think that we should firmly declare that this is not the place to proclaim your new method of interpretation and new theology.
No, it is not.
But the reason it is not is not that they are fringe beliefs, it is that they are personal and don't answer any questions of the form this site is built around. This site asks for the beliefs of various Christian groups. It is not a place for airing out new ideas, developing theology, evangelizing, or otherwise soap-boxing anything.
The world is full of personal opinions and unanswerable questions. Stack Exchange sites are not here to give either of those things a voice. Stack Exchange sites exist primarily to cut through the noise and make the best answers to answerable questions more readily available.
This goal is basically orthogonal to the goals of Christianity itself. It's not particularly lined up with Christian agendas or methodology --- nor is it opposed to them. However it is common to find people arriving on this site expecting it to line up with their own agendas or to be able to adapt it for such. This creates a tension that is only resolved when they either throw up their hands or adapt to using it only for what it happens to be good at.
Christians have a tendency to want to say things even if nobody is listening. We believe on a fundamental level that we have a message people need to hear and would be better off for having heard. I'm not judgmental of this (as a church planting pastor myself I am very aware of the urges!). The problem is when people become one-trick-ponies, and won't adjust their methods for the venue the find themselves in.
On Stack Exchange sites questions come first. Questions define the scope of possible answers for each question and collectively define the scope of the site. First come the questions then answers follow cue.
If you approach this site with the attitude that you have insights that the world needs to hear, you are doing it wrong. Answer the questions that people are asking, don't just fill the space with what you think they need to hear. Seriously. This isn't the place to get the word out. If you have fringe beliefs then by definition there are going to be few questions for you to answer on this site because your views are only going to be in scope when your fringe group is specifically asked about. If you have special unique revelation (whether from the devil or from God himself) that is not already part of an established group's documented belief system there will no place at all for those views. Go find another venue for evangelism.
Here, you must stick to answering the questions that were asked. If a question is so ill defined that it could be answered just as validly from one fringe viewpoint as another (or as validly as a mainstream answer) then the question needs to be closed pending a more defined scope.
This site is about what groups of Christians believe, not individual opinions.
We have established consensus around What is the minimum bar for a "group" (sect / denomination / etc..)?
We specifically do not do new theology here - we only seek to understand extant theology. We are more akin to a seminary than a church - this is an academic context in which academic questions are scrutinized and answered. It is not a forum, It is not a bar.
If God has called you to preach, he has already given you a context in which to do it. This is not that place.
fringe beliefs" - absolutely not. However we should be careful to not isolate the spirit of the SE to the point that we're just preaching to the choir. That is, if we only accept questions and answers from orthodoxy, then it should be stated that way in the definition of the site.
Asking for more information or clarification of a specific point in an answer is one thing - being antagonistic towards others is another.
"... very unclear whether they actually even believe in a god at all" this is not constructive to your question and potentially offensive. I do not remember reading that atheists could not participate in the site - I would welcome educated responses from non-Christians with references.
I have not looked up the posts that you are referring to deliberately, so that I won't be biased by their content before I write this reply.
In general, I'd say, "Who decides what is a fringe group whose opinions are not worth hearing?"
If someone is misrepresenting the beliefs of some other group, like if he says, "United Methodists believe that ..." and then proceeds to describe his own beliefs that have nothing to do with United Methodists, that is clearly wrong and he should be called out.
If someone uses every question asked as a platform to evangelize for his own denomination, that's wrong and he should be called out. I mean like someone asks, "Where was the city of Samaria located?" and he replies, "That is a very interesting question. Jesus taught that Samaria, like all other places on Earth, should refuse to accept vaccinations because vaccines are from the Devil ..." Etc.
But if someone says, "My understanding of this verse in the Bible is that it says that ..." and proceeds to give an honest answer, I wouldn't want to shut him down just because I disagree. I disagree with a lot of the things posted on here.
The whole point of discussing different ideas becomes a joke if this restriction is imposed. If you want to restrict it to only dogmatized orthodox thinking of various mainstream organizations on both sides of the questions and answers then I see no benefit to being here other than to keep my head in the same sand pit. Religion needs answers and it yet needs to be questioned. This site is useless if it shuts that off.