[vbat99]

Sounds like you have the option Download from Fanart.Tv during autoscrape selected. This will save the poster.jpg and fanart.jpg as well as disc-art and logo. Check Movie Preferences -> Scraper tab.

If i unselected Download from Fanart.Tv during autoscrape, i don't scrap clearlogo, discart, clearart... And if i download them manually, i don't have movie-clearlogo but only logo. Is it possible to add rename for artwork to have movie-artwork ?

The correct naming is logo.jpg,, seeing moviename-clearlogo means you have exported your library, and this is the format XBMC exports it in, but artwork downloader does not import this filename convention. But, if you have links to info that shows other naming conventions, please post those links. I'm all about getting it right.
NB: XBMC/Kodi does not import logo.jpg or moviename.clearlogo.jpg.

Setting the poster height, also in Movie Preferences -> Scraper tab, Set poster height to your desired size. IE: set 1080 if you want the poster size 1920x1080, or 720 for poster size of 1280x720, etc.

i have found this but i can't manually set 1280 and it doesn't exist in the list (i use 1280 with XBNE since the start and all of my poster are resized to 1280). Is there a way to add this setting?

MC is set to a max height of 1080, for 1080p (1920x1080) resolution. What resolution are you displaying XBMC/Kodi?

I have another question :
Is it possible to create a conversion table to automatically rename certain information such as genre and country names?
For example, at home, he gets as country name "United States of America" but I would like to have "Etats-Unis" and if possible to correct all the database if necessary.

No we don't have a method of converting this. We get the information from IMDB or TMDB. I assume from your results that Genre's and Country are not stored in different languages.

I am not sure, but Notepad++ may be your only method to mass edit nfo's, searching for United States of America and exchanging it for Etats-Unis. Same could be done for Genre's, but for now, this is outside the scope of Media Companion