How to Manage Posts from All Sites in Multisite Dashboard in one place
I begin with the screenshot.

Yes, it is not fully-functional Posts page, so you can see, that there is no Screen Options tab, no archives by dates filter, no quick or bulk edit options. Anyway, if you got the idea and you need to show posts from all blogs on this page, you can download my plugin here.
By the way, do you know how to add pages in Network Dashboard? I did it this way:
add_action('network_admin_menu', 'misha_add_option_page');
function misha_add_option_page() {
add_menu_page( "Multisite Posts", ...
...
}
Read more about creating option pages in WordPress multisite dashboard here.
Edit, Move to Trash and Preview Multisite Posts
When you click Edit or Preview link you will be redirected to the appropriated pages of the website whene the selected post is located. When you click Trash, the post will be moved to trash and removed from Network Index via AJAX.

Order By Title and by Date
If you click on table headings, the posts will be sorted ascending or descending (second click).

Search for Network Posts
Search works pretty good with pagination. If you’re looking how to implement multisite search on the website, not admin area, I recommend to look at this tutorial.

So, you can read more about this plugin here or if you feel the lack of features, just add a comment below and I suppose I can help you with it.
Multisite-related articles

Misha Rudrastyh
Hey guys and welcome to my website. For more than 10 years I've been doing my best to share with you some superb WordPress guides and tips for free.
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Oh, another question: does the plugin support custom post types? Especially post types which are added by plugins that are NOT installed network-wide?
Yes, it supports post types which are added by plugins that are activated only on a certain website.
Hey Misha,
Is it possible to move posts within the site network
Hey John,
Currently no, but I like your idea!
Hey Misha,
I need a feature to have all posts listed on single dashboard so that admin can approve posts. The idea is that author will have posts only in draft mode, then admin approves his post on his site. I suppose this case is possible via your plugin? This network dashboard comes out of the box, or you need to do a bit of custom coding with your Class for it?
Hey Goran,
The network dashboard mentioned in this post comes out of the box, yes.