Support for multilanguage sites, Internationalization (I18N)

[mvlcek]

However, when clicking through the site I noticed that the parent page needed for the 2nd menu is also shown in the browsers address bar, plus the name of that page shows up in the breadcrumb.

Basically this is totally logical, since these page were added using the parent/child structure but is there a way not not display the parent page of the 2nd menu in both the address bar as well as the breadcrumb?

Use fancy URLs without %parent%.
Build the breadcrumbs programmatically with PHP using return_i18n_breadcrumbs (look at the get_i18n_breadcrumbs function in the plugin and copy/modify the code to not include the first breadcrumb).