1) chooseAsync = Change context in C3. (switchAsync and createAsync you can use via js, but is rarely used in IG)
2) For newly created games you can only create contextual leaderboards. So only use this in your projects from now on.
3) iap is not supported in C3 plugin. Use js
4) You don't need this, but can do it manually if you really need
5) This is supported in the plugin, but is cotrolled by FB. Now it gives a message to share on your wall. but changes from time to time.