There are three separate issues in your question.
(1) The possessive before a gerund phrase. In everyday English, these are both widely used:
She's annoyed about my being elected class president.
She's annoyed about me being elected class president.
The former is traditionally viewed as more correct, but it's less common nowadays (at least in North America). People might even assume you meant to say the latter.
(2) A proper name before a gerund phrase. This presents no problem whatsoever.
I'm happy about John's being elected class president.
I'm happy about John being elected class president.
(3) A whole phrase before a possessive. This varies widely. When a possessive is attached to a noun phrase of several words, it can be hard to interpret or awkward. I think most people would agree that this is "not standard", even though you certainly do hear it in conversation:
Are you really going to the guy who insulted you's wedding?
My instincts tell me this is best suited for oral use only. Otherwise, it can usually be rephrased:
Are you really going to the wedding of the guy who insulted you?
On the other hand, proper names are usually just two words and thus much easier to understand:
What do you think of Mel Gibson's being Australian?
Nobody would find this awkward because of the proper name. They might not be familiar with the possessive before a gerund, as mentioned above under (1). But a pedant can always defend that choice if needed...