Re: emulated buildds
Aurelien, your claim is wrong. About a year ago (IIRC; might've been longer), the Debian/m68k team decided that it wanted to do emulated buildd hosts, since that would allow us to more easily keep up with unstable. We discussed it in the team, we discussed it with ftp-masters, and we all decided to go for it. We've had emulated m68k builds go to the archive for quite a long time, with full knowledge and agreement of ftp-masters. We realized that emulated builds could be problematic, but we evaluated the issues and decided to take that risk, as a team.
The reason your key was rejected for uploads of arm binaries was because you started doing those emulated builds without discussing it with the arm buildd maintainers, and without discussing it with the arm porters. You just decided it might help, so it must be good, right?
Finding the difference is left as an exercise to the reader.