Guys, I current having difficulty in understanding how PSN works.

1) Currently having one PSN acc, under Asia, subscribed with PS+
2) Registered an US PSN and sign in Ps4, downloaded a theme, switch back to Asia PSN, but cant activate the theme as it was locked.

My question is
1) Do I need to make the US PSN as primary in order to play the downloaded games and use the downloaded theme?
2) If US PSN is primary, can I still use the PS+ feature on my R3 PSN?
3) If US PSN is primary, can I still play the game on the Asia PSN?
4) Lets say i have Destiny on my Asia PSN (hard copy), can I still use the same ID when playing it on US PSN or I have to start the Destiny all over again?

I read few post on this but ended up getting myself confused. Reason for setting up US PSN is that they have more content and sales

This post has been edited by rayz1031: Apr 25 2016, 03:53 PM