Hi ok there is the long list of shortcuts in ck but wich ones are the most usefull to remember always ? I just forgot from the last time I worked on landscape ... I remember something that didnt allow the selected items to disappear when u get more far of some cells ...

wich others are usefull ?

With the landscape editor open:

1-9 set the brush size to 1-9 instantly.
S toggles 'smoothing' mode.
F toggles 'flatten' mode.
Control+Right click sets the active texture to the one you right click on.
H Opens and closes the landscape editor.

Those are the main ones I use. (Well except flatten, I never ever use that as the results look horribly unnatural)

I remember F5 to refresh the viewport
1 or f1 to cicle thorught transparency mode of some items
but I dont remember how to lock the popping upp and off of the elements you have selected ...

This can help you remember some of them:
http://www.creationkit.com/Creation_Kit_Keyboard_Mapping

Indeed.

Of those, F (Drop ref), H (Toggle land editing), T (Top-down cam view), F5 (rerender), S (Scale ref), B (Toggle cell borders, exterior), and A (Toggle lights) are perticularely useful. I use 'em all constantly. Oh, along with Q and Control+Q for the snap toggles.

thanks for all now I start to remember but I still don't remember that specific key to not allow the selected items to disappear due to cell loading , I don't mean freeze the whole cells in wich u where in but just the selected objects .. befoure I coudl pick for example a set of stuff and spin them around many cells distant even if it was in lod terrain area , now I can't as they disappear ...