Yeah, I don't see why "Private anyone with the link" wouldn't work for your security concerns, as long as you have an email address to send the link to, but if nudity is expressly forbidden, even in private albums, then you do have an issue.

My own use of Picasaweb has been pretty much unaffected by the move to Google+, but that use is mostly sharing with family, not clients and customers (of which I have none, not being a pro photog.)