You are a wise man!
The ATF has been forever a rogue agency. That was true at Waco and, from what I’m seeing, is still true today.
It’s not just the BATF, I’ve read stories about the FBI and Justice Dept that really make you wonder what side they may be on?
In general, one of the best reforms I can think of would be to return most of the Departments to agencies in the Department of the Interior, forcing them all to become one level of organization smaller.
The ATF, however, should be further restricted to being a division of the Bureau of Indian Affairs, and only have jurisdiction in Indian Country and federal lands.