Wist, the way I acclimatise my boys is: leave it for 4 wks, then attach the nose lead rope to the ring but tie it to his halter when leading, don't use it. I do that for a few days then I'll pick it up and use light pressure. Remember its your brake, not your accelerator. Try not to pull him forward with it, pull forward on the halter and the nose is there to stop them if needed. However, having said that, when I need to pull a bull out of a bad situation (fighting another bull, about to jump a heifer etc) I have pulled on both halter and nose and it does work. But thats in extreme cases.
FWIW re the heifer in heat question, I thought it was about the bulls wanting to chase heifers in heat too. And I do the vicks trick on the nose also. Re stroppy females in heat at shows, I've never figured out a way to deal with it, a lot of ours were excitable travellers so the actual getting to the show was enough to bring them into heat. It sucks.
Also, I hate to disagree with harley because I truly do admire and respect everything that comes from him, but I find the idea of walking the bull through a paddock of unrestrained animals a little unnerving, frankly a little dangerous even. If those steers don't know him they might come over, they may very well start bunting him in the head/butt, and for starters a) you don't want to accidentally wind up in the middle of a dominance butting competition and b) if your little bull decides to turn around and give them a flogging, even with nose ring if he really wants to, you wont be able to avoid it, not even with the most well trained bull. I've been there and its not fun. So I guess, I wouldn't be doing that, but if it works for you then keep doing it.
