Use either PluginTR for the headings in the page that end up in the table of content (with maketoc) of your single wiki page, or translate full page to each language and let tiki sync page language to site language. See more information through i18n
Register at tiki.org and you'll be able to use the account at any *.tiki.org site, thanks to the InterTiki feature. A valid email address is required to receive site notifications and occasional newsletters. You can opt out of these items at any time.