Currently no multi lingual versions. German is meant to be coming real soon now.
User Dictionarys; no means available to add your own.
Fonts; you need a directory called "fonts" (exact case) in the root of the Kobo. Then True Type / Open Type fonts can be placed there. See https://www.mobileread.com/forums/sho...5&postcount=46
for some info on how they should be named.