I have my own Gedcom tree and wanted to try Geni, but it is getting tiresome very fast. Obviously nobody thought about non-US users and therefore I stopped using it and deleted my entry. I make a seperate Bug report for each feature.
The entry of dates is most annoying. Most of the world does not enter the date in the wrong order MM.DD.YYYY but as DD.MM.YYYY - and even if I change the language to German the localization is still wrong. This is prone to errors, for obvious reasons. Don't make it so hard for your users.