Hi RipleYYY ... nice to hear from you again! Congrats on your new Hot Wheels, hope it gives you and your family and friends lots of fun!
Re: the two red circles in your image: to my knowledge, the left one is a known place where the ball can get caught if it's moving slowly -- not "permanently" caught, but enough that you may need to nudge to free it, which could be an issue if you have a tight tilt. I have a brain cell tickling me that there might be a fix available from the factory to improve this, a tweaked rail or post? Not sure -- don't hesitate to file a service ticket at <https://www.american-pinball.com/support/service/> to see if they can do anything to improve that for you.
I'm not sure what the story is with the right red circle in your image ... that's not a common ball trap AFAIK. If balls are getting stuck there on your game, again, please contact API Service to see if they have any solutions for you.
As for your question about replay settings... the default should be 1 replay level. That should be the green (factory default) value for Settings > Replay > Replay Levels. You're right that the default replay (score threshold) award is an Extra Ball. Of course, adjust these to suit your taste, along with other Extra Ball settings specific to Hot Wheels (Car Collects for Extra Ball, Hero Cars for Extra Ball). Personally, I like replay levels (1) giving me an extra ball -- free credit is useless at home -- with Automatic Replay Percentaging turned on and Replay Percentage around 5%. Getting to Legend Multiball is not easy on just 3 physical balls. Become a Hot Wheels (Legend)!