Here's my 2cents worth...
Horn upgrade? Absolutely! I went with a Wolo Badboy, very similar to the Stebil Nautilus, but around $40. Stock horn's a waste of effort POS.
I have pulsation from my stock fronts on my 2011. Started around 4000 miles. Got 17k miles now.
You might try what has helped me... Instead of spending money on it, or having them replaced under warranty...( waste of effort) i now stop 85% of the way using just the brake pedal. Then, right before the stop, I then add the lever, and bring more of the fronts in. This has reduced the pulsation a bunch.
Seems to have prolonged brake life, and the problem does not seem to be worsening.
Just a suggestion, based on my experience.
Does it at least need a good throttle lock? Absolutely! I installed a Throttlemeister. Then installed a Rostra. Best farkle $$ I've spent so far.
I also added 2" dropped peg brackets, AST touring pegs, Cee Bailey's HDUT windscreen, driving lights, tip over protection, fenda extender, phil's rack, 2" risers w/ Phil's wedges, Kawasaki Gel seat...
There are all kinds of things you can choose from. Do whatever improves it for YOU.
Now, if you really are offering to give me your $$ to spend... you've come to the right guy! I can do it...
Lol!
Bob