Is cocos2d-x support both ARC and non-ARC for iOS from the ground up?

I’m studying about this topic recently and would like to know whether I have to go for full ARC code, or (my preferred way) non-ARC.

Also, can I just set the build setting and cocos2d-x will follow it ?

No yet. As you can see, cocos2d-x mainly use its reference count based memory management.
ARC only affects a few input/output classes.

If I mix it with objective-c code to invoke native UI or anything else, will that be any problems ?

Bump.

I’m trying to mix UIKit and Cocos2D-x while keeping ARC enabled, but I’m running into problems?