Advice on Panasonic 35-100 purchase

Looking to purchase the Panasonic 35-100 for my GH3.  Rather than spend $1250+ on a USA version of the lens, I was thinking about buying a Japanese import version from Amazon Marketplace (I have some gift card balance to use).
Before I buy, I wanted to ask those who have had experience buying this way how it worked out.  Specifically,
1). How does warranty service work if it is needed?  Will Panasonic USA fix an import version, or does it need to be sent back to Japan for service?
2). I assume there are no cosmetic or functional differences between the versions and it will be fully operable with my GH3?   Same firmware updates as well?
3). The featured seller on Amazon is AkibaExpress, which seems to have good ratings.  Has anyone purchased from this Japanese dealer here or are they recognizable?
Thanks!  Any other suggestions/recommendations are welcomed.
Travis