I think he does too. My theory is it is a younger woman, probably someone who works nights. In order for him to have someone help him w/o knowing who he is, this person has to not really care about the news or read papers (either online or otherwise). This person would be out mostly at night thus avoiding seeing the flyers (because it is dark), and sleeps during the day. This person would have to be fairly easily manipulated (younger than him).
He's a fairly good looking guy, probably articulate, a smooth talker. I could see him manipulating a younger girl with self-esteem issues into helping him.
I'd put a lot of flyers down near bars and where nightlife is most active.
I agree with your theory. I'll also add that news about Lynn's murder has fallen off the radar for most major big city news outlets in Ohio. Once her body was found in NC, the news coverage really slowed down, with very little recent coverage of the manhunt for Nathan.
For that reason, its very possible that someone could be helping him who isn't aware that he's wanted for Lynn's murder. Perhaps we need to get the news media in the big cities (Cleveland, Toledo, Columbus, Youngstown, etc.) to run some stories about the manhunt for Nathan.