I do like that feature about DMR, and hope that will keep folks honest.
I don't know if someone can just use another user's ID on the network, but I hope not.
I'd hate to get banned for action that someone took using my credentials.
The problem with a digital radio, is it has to be programmed. As such the ID needs to be set in the programming to have the radio have what ever ID it needs.
So YUP, you can spoof what ever call sign and ID you want.
But getting back to the original question, the way people use the repeaters and HF frequencies really depends on how others operate on the radios. You can tune in many conversations on HF and find everything from heavy swearing like your in a bar to some really technical conversations. Just which conversation you get involved with will probably depend on what you like and how you became acclimated to the conversations.
To expand more, the future of the "Ham Radio" activities will depend on how you all allow poor and good operating practices to continue. There are many that have indicated that overall, the ham radio activity has declined. This statement I have to agree with that the general activity has dropped. But if there is a contest weekend, you won't be able to find a frequency on HF to slide into and have a normal conversation.
I like to get into the radio technical activities. But the average ham operator today has become an appliance operator. In many cases, these operators have a hard time trying to see where the power fuse is.
As for the repeater activity and the type of conversations they carry, this also depends on who are using the repeater and how tightly the action is controlled. Do I support people breaking the FCC rules and causing interference? No, and I do help track down those that are causing the problems. Does the FCC act on these problems? Not unless it has become a major issue. Their hands are tied to some extent with the budget cuts that have been in place for a number of years. It will only get worse as we go into this new administration.
I hope I have not strayed too far off of the original question that started this thread.