I'll have to go back and catch up, but just wanted to make a quick comment.
These guys you're talking about at 2 or 5nl should be super simple to play against for the exact reason you mentioned above. They just call. So you just keep betting until they raise, and if they raise, it's the easiest fold ever. You should play for maximum exploitative value by betting larger when you have big hands, and smaller when you have weaker hands. We want to keep this within reason, but I can show you examples of recent hands at 100 and 200nl where I do this against non-aggressive fish, and I can bluff for the minimum, extract value from tons of second best hands with my bet sizing, and get them to call down with bad draws against my strong hands with large bets.
Will they hit their hand sometimes? Of course, but if you have a value hand it pretty much illustrates my point #3. Would you rather be betting your hand and controlling the sizing of the pot, or check / calling against someone like that? You're not check / folding when you have a value hand, so experiment with different bet sizing based on the board texture and your hand strength. Focus on what second best hands you're looking to call based on your sizing.