Some of the features you seek fall in the realms of add-ons or integrations.
The recommendations for video would depend on whether you want the video easily accessed by most people or locked down to subscribers only.
If general access is OK then integrating YouTube Live or similar makes a lot of sense.
If you want your Videos locked down to subscribers only then a paid solution like Kaltura or Panopto might make more sense.
The language packs to change the system language already exist for lots of languages including Arabic and further customization of those language packs is trivial to do.
I'm with Dan here, engage a Moodle partner to get clear costings and capabilities.