Why are there no dates on main site posts list? It’s hard enough to see who posted it. And with no date reference - it's not even clear how relevant it is

There are no dates because it's not meant to be a time-sensitive material.
Though...I see why you are asking, instead of the regular-site-like main page, there is a blog-site-like main page.

Quite a few of the pages are put out with an intention to be rewritten/improved.

Except the blog part....for which I took your suggestion and changed it to display date.

Btw. content is mostly written by me. I plan to rather open another site, for some time already, that will be completely user-driven community, on http://www.procrastination.ws (nothing there yet). That one would include date and author references etc.

Well, pagination wise and visually it is looks very blog like - since there is a rolling feed of articles rather then fixed pages. I also think Blog architecture pretty much can handle what you need - that is: time sensitive articles as well as directly linked static pages.

I'd still argue - that any content should be time stamped.

Also, I’m not sure why do you need a new site? This one has good search ratings on Google. Plus it makes me question: what is the purpose of this site then? Why not just improve this one?

The new one, was intended to be completely community-centric. Discussion forum would be more prominent, and people could write anything from blogs to articles, to shouts on shoutbox.

Whereas this one was originally intended to be a one-writer simple static site.

I feel these two concepts don't go well together on one site unless some trade-offs.