i doubt the state wants to "lower the boom" on MBs. i think one cop was having a bad day and decided to hassle you.
you say you read the whole safety act. i think you missed the words "motor vehicle" a coupla hundred times in your search for the words "motorized bicycle."
the one section that mentions busses, cars and trucks is mostly about airbags and safety restraints. since none of them are on a 2 wheeled vehicle, there's no point in mentioning them.
sure, the act was repealed. to change the name. in your first post, it points out that everything is pretty much the same as it was before.
a cop can't impound your bike as long as it's registered and you have an M2 license. unless you have a warrant, are drunk, whatever. lights, horn, etc are all fixit tickets.
if he wants to be a jerk, he could write you up for anything.
what YOU should do, is smile, take the ticket, and go away.
the law is clear on the equipment requirements. if you go to court and plan to argue some obscure motion about the law being repealed and only applies to busses, you better have a good lawyer. and a lot more money than it would cost to add a horn to your bike, or a mirror, or whatever.
you also better make sure it's a motorized bicycle under the letter of the law. under 2hp and 30mph. can't be modified to go over 30, etc.
if you're gonna make a big deal over nothing, to get back at the cop who made a big deal over nothing, then the judge is probably gonna make a big deal over nothing.
this isn't cannonbal run, or the haymarket massacre, or ruby ridge. this is a cop in a bad mood and a kid on a bike who won't respect him.
didja see the video where the LA cops (one of them a 20 year veteran) beat up a chick for using her cell phone while driving (the "knuckle bump" at the end is classic...)
http://www.youtube.com/watch?v=EHYMS44lI34
i got a ticket in Newport Beach a long time ago for not wearing a DOT helmet, no M2, and no registration. i was polite without kissing ass, and rode home with a $395 ticket. i got a helmet, got a permit, and got a plate, and went to court and paid 75 bucks in court fees.
my step dad's advice still rings true; "if you're gonna tell a cop to go **** himself, wait til he's already left."