They'll all have a sun synchronous polar orbit.. I don't think they'll be very low orbit, unless they are like trains, at every 1km a satellite.

And it will impact negatively humanity's health.

https://engineerine.com/starlink-satellites-harming-human/

Not really, if you look at the plans, only a few hundred thousand satellites were planned in LEO, and millions over the Chinese satellites.

There will be a collision at some point, there's no real-time communication between USA and China satellite launches.