OK, it was interesting to find the real reason why you wanted to change your calliper bolts to stainless.
I had never seen caliper protectors, so wondered what really useful service they performed, given the usual general levels of destruction metered out to motorcycles in a serious enough mishap.
Seems they are just bling; which is fine.
Bling away; people make money from it, it boosts the economy and keeps foreigners in employment.
PS. Rather like personalised number plates, I have never really got the whole 'personalise' your bike thing. Anything I have fitted served a purpose, but even that got tedious after a while. Less is more in my world now. I have taken up (or more honestly, rediscoverd) the delight of touring on an outright sports bike, unblinged except for a simple generic GPS mount and an option to fit some Ventura luggage. It came fitted with heated grips, which seem to work, so even those don't need to be worried about. One lead for a heated vest and all is good to go for two thousand miles, rain or shine.
Exhausts and all that old malarkey, I now leave as is.
Aftermarket fuelling aids, re-maps and other must-does? I find it easier to turn them into don't-does.
If I were to change / 'improve' anything? It would probably be the suspension on many bikes but the new 'smart' electric systems are getting pretty good, straight out of the box. My 1600's is getting a bit saggy at 32,000 miles which is not unexpected on a 320 kg bike that is worked pretty hard. It will either be staying BMW's own (it's been OK, just left on two-up, sports setting) or maybe a look at the comparative price of some alternatives, like Wilbers.
PPS The only bit of (useful) after-market add-on that I have in mind for the sports bike is an oil cooler radiator guard. I have never bothered with one before. The oil cooler sits naked, very low down behind the front wheel. After 6000 miles it is showing signs of the peppering it is receiving from road debris, flung up.... Not a problem on a track, unless you hit the kitty-litter... One decent sized stone and bingo... You can bi-pass the oil cooler in an emergency... But (sensible) prevention may well be better than several hours of cure at the roadside.