Space is big, even LEO. As long as the large majority of all satellites have active collision avoidance, and coordinate between them, this shouldn’t be a problem. I’m not sure if there’s an international body working to coordinate this, but there should be.

Starship, if successful, will also change the economics of bringing down non-maneuverable satellites. I could see SpaceX cleaning up space junk as a public service.

Uplink/downlink bandwidth is licensed by the countries being uplinked/downlinked from/to, so that’s on them. China will no doubt not grant SpaceX a license.

Lots of space tech is “dual use”, e.x. GPS and many other communication satellites. As long as SpaceX isn’t hiding warheads on Starlink satellites or something I don’t see a problem.