LMAO 8 reports for attitude????? Dude, unacceptable. Are you serious? Totally unacceptable. Kidding man! Still laughing!!!!! 
Bro that's exactly what I do. I'm always super friendly at meet-up, say Hi , how ya doin, where ya going. Then I throw a feeler out there, weather usually or something else general. You can always tell how they respond if they're interested, or not, in chatting. If they are friendly and seem enthusiastic, of course the conversation will just flow. If they're not, then I just shut up and drive. Honestly it's worked super well for me so far. If they want to talk, I always talk. If not, just get that vibe and keep the radio on low. Agree it is tricky. And pax shouldn't rate low for it unless the driver is being obnoxiously annoying.You are damned if you do and damned if you don't. If you talk too much customers complain but if you don't talk enough they still complain. The customer should set the tone. We aren't mind readers so we will just be quiet until spoken to.
All depends on how much you care about your rating. If you don't and 3's and 4's are OK, then it's all good. It is a job that does require a decent level of customer service. Granted its definitely not a ton of money, only a supplement, but if you want the rating and/or a tip, you gotta play ball a little bit so to speak.I just say hey are you and that's about it. I let them set the tone. I'm nice but not overly nice to the point where it looks like I want to wipe their bottom. I'm not an uber black driver lol