Call quality is ok. Not the best like the Airpod Pros but it is decent. I've talked to people on the phone and they didn't seem to realize I was using earbuds instead of just talking into the phone. Yes you can use a single bud either left or right independently.
That's tough. I think OnePlus has more of a balanced sound with more detail... But the Nothing ear (1)s have deeper bass and good mids but the high end gets muddied some. Not a whole lot and for $99 these are amazing. It's just based on your preference.
