[quote=tzfujimino;338363]
1. In my humble opinion, 'who' functions as a subject.

2. Yes, I believe they are both correct.
The form
been (to) refers to something that somebody has experienced through the action of
going somewhere, and usually having returned from that place:
I have been to Greece once in my life. = I went to Greece some time ago, and have returned.
The other form
gone (to) refers to the action of
going somewhere, but not having returned from that place yet:
She has gone to Greece. = she is on her way to Greece, or she may have reached there already; she's certainly not back from there yet. (quote) engee30