My writings are often, the product of risky intrusions
(!), and of laborious amateur experiments.
For me, it is essential to raise unexpected new questions in the reader's mind, so that the narrated events must look likely to occur in the real world.
How does this forum ensures us that any person from outside can not steal parts of the texts exposed?
Technically there isn't really a way to protect 'intellectual property' ** unless (and even then its messy) you have bottomless pockets and a lifetime to fight your corner.
My experience with this site, say in the critique areas, is that people either post extracts from their work that are 'test pieces' or sections of a main work which could not possibly give too much away about the over all plot of their book.
Obviously this does sometimes happen, but there are usually friendly reminders that publishers sometimes look badly on a book if half of it is freely available in draft form on a forum like this one.
In any case, the 1500 word limit would make it difficult to reveal the delicate intricacies of someone work unless they submitted a chapter by chapter review of their book - and what would be the point of that.
OK, you could introduce 'novel' concepts that you think will make the basis of a good story (this does happen occasionally), but in that case why do it if you intend to write the book yourself.
In general (although this is a free to view site) the people that post on on site are either, up to their neck in their own project, or have no interest in writing at all (although they do like a good argument, read, intellectual challenge etc.)
If you come up with the secret of eternal life (something I do have going on in the nether depths of this site - even as we speak) then the usual 'patent' law applies. Don't reveal your secret before the enough cash has rolled in to enable you to defend the patent.
OK, Black and Decker are good at this but they defend their patents around the world on an almost daily basis.
So my advice is, post, but be aware, this site is publicly available.
** In fact unless you have bottomless pockets, all a patent does is tell your rivals what you are doing and how to do it.