I would like to move windows with keyboard shorcuts. Even thought in KWin Keybord Shorcuts menu I see some global shorcuts like:

Move Down (Meta + Down), Move Left (Meta + Down),...

Move Window Down (Meta + Shift + J), Move Window Left (Meta + Shift + H) ...

But none of these seem to do anything. Do I have to turn 'moving by shorcuts' feature on? What do these actions do? What am I missing?

Also what would be shorcuts to resize window and to center it into middle of the screen?

rsupremo wrote:I would like to move windows with keyboard shorcuts. Even thought in KWin Keybord Shorcuts menu I see some global shorcuts like:

Move Down (Meta + Down), Move Left (Meta + Down),...

Those shortcuts are for moving the zoomed area when you have desktop zoom activated, i.e. press Meta+=.

Move Window Down (Meta + Shift + J), Move Window Left (Meta + Shift + H) ...

But none of these seem to do anything. Do I have to turn 'moving by shorcuts' feature on? What do these actions do? What am I missing?

Hm, I don't have those shortcuts here.
The only vaguely similar option I see is "Move Window Down a Desktop" and so on. (I'm running in german here so I'm not 100% sure how they would be named in english)
Those are not set by default here, but they are for moving the window to a different virtual desktop obviously.

Also what would be shorcuts to resize window and to center it into middle of the screen?

You mean maximize it?
There is the possibility to use a shortcut to maximize the activated window, but you have to assign one first by clicking on the entry in the shortcuts settings.

And there are shortcuts for resizing/moving the activated window as well, but again you have to assign them first, they are not set by default.
You can then switch to resize/move mode by pressing the key combination you set, and use the cursor keys for actually resizing/moving the window then.

I don't see any possibility to assign a shortcut for centering a window though, if that's what you mean.

Both shortcut variants are relics from the interim tiling WM support (and would not have done what you likely wanted) - zooming meanwhile has a speaking name (move zoomed area) and we hopefully shipped a kconfupdate script for that

What would work is "pack [shrink] window", but is likely neither what you want.

And there are shortcuts for resizing/moving the activated window as well, but again you have to assign them first, they are not set by default.
You can then switch to resize/move mode by pressing the key combination you set, and use the cursor keys for actually resizing/moving the window then.

This is likely the best answer to your question - shortcuts to move/resize windows directly this way have never existed.