At cs.wv it is common to add signature with timestamp into the pages of the main ns. Would it be possible to add such option to VE?
This has been declined before, since VisualEditor is not meant for talk pages (and talk-like pages) and wouldn't work well on them even if someone decided to enable it.
However, there's a script available that adds such an option: https://meta.wikimedia.org/wiki/User:Matma_Rex/visualeditor-signature.js. It's not officially supported by the team, but I try to keep it working (assuming that someone lets me know that it broke).
To enable it, you need to add the following line to common.js (either your personal User:Whoever/common.js, or wiki-wide MediaWiki:Common.js):
To enable it in all namespaces where VisualEditor itself is enabled, also add this line before that one:
mw.config.set( 'wgVisualEditorNoSignatureNamespaces',  );
(By default, it is only enabled in non-content namespaces, so in particular not in main namespace.)
So there are no plans to use VE on all types of pages (i.e. namespaces)? It does not look to me logic to provide new and feature editor of main pages and push them to study difficult wikitext, while they want to have a discussion about the article.