[Karellen]

I'm running into issue 2 a lot because i use Emby Server. When it scrapes the movies it gives you anywhere between 1 and 6-7 studios.
How does Kodi decide which studio it will use at the moment? I have very different results.

Simple. If there is one studio it uses the icon image of the studio if available in the resource pack. (If it is not, please contribute the studio logo)
If there are two or more studios, then no icons are used.

To check what is happening with your movies, export your library to nfo files and open the nfo file and check the studio tags.