Hello Justin and a hearty thank you for your offer!
I would concur with your points about dead ends and limited success in the tracking of records the 1600-1700's. I've been concentrating on my maternal line these last couple of years and one really has to keep an open mind throughout. Not only can records not exist, ones that do are full of errors; in transcription, due to oral reporting, variance of languages and literacy, all sorts of reasons.
Tom Ryder, the initial Arney researcher of note, has pretty much exhausted the PA Archives, and long ago. He made an error, discovered it, and has made a concentrated effort to make sure we all know of it. He's been tremendous help to us following him.
If you're inclined, I'd say that Trinity Lutheran Church Records and Old Kreutz Creek stuff would be where I'd first look. These and so much more are housed or accessible here at Lancaster County's Historical Society. They're going through renovation, so might want to review this... http://www.lancasterhistory.org/index.php?option=com_content&view=article&id=234&Itemid=127http://www.lancasterhistory.org/index.php?option=com_content&view=article&id=234&Itemid=127