I do not want any emissions crap on any of my vehicles, plain and simple. The key words there are "do not want" On the Vulcan 750 these systems can and do interfere with the proper operation of the bike. But I would have gotten rid of them even if that had not been the case. I do not believe the government has any business interfering with my vehicles, during design, manufacturing, or once I buy them. I simply undid what I feel should never have been done in the first place. On the Vulcan 750 it was cheap and mostly easy, though it took a while due to the sheer volume of what had to be removed. On a new bike, it gets very expensive. It has EFI and catalytic converters in the stock pipes. You have to replace the stock pipes, then buy a $500 electronic tuner to remap the ECU to make it run properly. Somewhere in the neighborhood of $1000. Plus if it is a new bike you probably void your engine warranty (you do with H-D) If I were planning to buy one of those bikes, I would figure that into the price. I have been fighting the EPA for more than 45 years, I'm certainly not going to stop now. EDIT: I just saw a thread where someone broke off a bolt in the head while trying to remove the reed valve cover. It really pisses me off that this bolt was only there because of the EPA.
The brake and throttle modifications on the other hand were made simply to improve function. I converted my front brake from an on/off switch to a perfectly functioning and easy to modulate brake, which has way more than enough power to lock the front wheel at will. I proved it to be safe during over 80,000 miles of use. Many larger and heavier bikes, especially cruisers, came with only one front disc, which worked fine. 2 smaller less powerful brakes should have worked fine, but why the added unnecessary complication? As for the throttle, all bikes used to come with a single throttle cable. It worked fine. Then someone decided to make it more complicated by adding another cable. That added twice as much cable and twice as much friction to the system with no improvement that I could see. Open your throttle all the way, then hold it open at the carbs, and try to close the twist grip. All the other cable does is bunch up at the carbs. I own a Honda Rebel 250 (I've had four) and over the years saw several posts about sticking throttles that turned out to be the "extra" cable binding in the housing. A sticking throttle on a motorcycle is not a good thing. So I removed that cable from my Rebel. I instantly noticed how much better the throttle felt, and how it snapped back so easily and quickly when released. I did the same thing to my Vulcan 750 with the same results. It became obvious that instead of making things safer, the extra cable actually made things more dangerous. That modification has also proven reliable and safe over a lot of years and miles. I also remove the "nanny" switches on the sidestand and clutch lever. Those are obviously not necessary. Lawyers are probably the reason they are there. Just learn to ride. If you are a beginner, do what I did. make a checklist and tape it to the tank. Read it every time you get on the bike. It will become permanently ingrained in your memory.
And no, the Vulcan 750 does not need all the parts it has. It does not need four camshafts, four cam chains, two jackshafts, eight valves, four spark plugs, or two carburetors. Other bikes run just fine with only half as many of all those parts. Some parts you can remove, some you can't. I just saw a post about someone putting a single carburetor on a Vulcan 750. I believe this would be an improvement if it were properly designed and manufactured. But it is too complicated to rig.
Many people run car tires on the back of a motorcycle. Common sense would seem to say that is unsafe. It seems obvious that a car tire has the wrong profile for a vehicle that leans over in turns. Yet extensive use over millions of miles without a single accident caused by doing it has proven it to be safe.
Many people tow trailers with motorcycles. Something I wouldn't even consider. It might work just cruising down the road, but would, at least in my opinion, turn into a disaster when you needed the handling and maneuverability of a motorcycle to get out of a sticky situation. I can't find any statistics about accidents that were caused by towing a trailer, or that may have been prevented by not towing a trailer, but I am convinced it is dangerous, and won't do it.
Does riding a bike with rear shocks that are two inches to short and that do not have the load capacity of the stock shocks make it unsafe?
Everybody has their opinions about what should or should not be done when it comes to motorcycles. And they are going to disagree. Having been an auto mechanic for 38 years I have a pretty good idea how things work (except for computers, but then that really has nothing to do with mechanics) I have built hot rods and race cars. I tend to think things through before I do them. And so far that has worked out good for me. Hopefully others will put some thought into their modifications beforehand, and not have to find out the hard way that it was not a good idea.