Yes, only use maps since Waze will redirect you onto surface streets to save an insignificant amount of time with a large amount of inconvenience.

Yes. I've tried Waze, and the only advantage it has is showing where cops are (which isn't very reliable, the data is frequently out of date and it shows cops where there aren't any, or doesn't show ones that set up their speed trap recently or are on a rural road).

Google Maps will show you alternative routes as you drive, telling you how much extra time they'll take (or save). Waze does not do this, it only shows you one route. I frequently want to take a slightly different route than the one shown, perhaps because I'm coming to a stoplight and it shows the alternate route of turning right to be "similar ETA", and by turning right I can avoid spending 1-3 minutes at the light.

Basically, Waze is just too minimalist. I want more information, not less.

Waze and Google Maps are the same team run by the same management.