How to handle virtual currency purchases when having game on iOS, Android and Web?

There seems to be lot of rules where IAP violations exists applied by each store.

Consider we have set of games where they use same virtual currency for the user account. How and what measures we need to take to make sure we are store complaint?

Queries
1. As its being a global game, can we have credit card purchases all over? If so are we allowed to do on Apple and Google mobile ecosystems?
2. How can we use IAP virtual currency bought in one app to be used in another app? Are we restricted any way by the platforms?


Any help would be greatly appreciated!

 

Interesting concept, I will check! I don't believe this is currently possible.