Lots of this lots of that go buy big cc ect comments.
here is the worthy best performance parts with useful comments;
To better something first you need to focus on the worst parts. As matter of fact that the worst part of the bike as stock is tires (unless you ride in USA becouse irc tires and the asphalt type USA is perfect match) .you can change tires to rosso or pilotstreet or battlax depending on your expectations from tire (performance / durability / combo)
Another issue that the most power loss occurs by transfer from front sprocket to rear wheel sprocket. For this issue i advise to use DID chain prefably xring and Esjot sprockets . better sprocket combination with better chain will achive higher power transmission.
Also there is a issue with head light. luminosity of the head lights are very standart , i would strongly reccommend to use a led head light such as novsight with 6500kelvin with 16000-18000 lumen. This really increases your night drive capability and safety.
Minor performance increase will be achieved with performance air filter and after market exhaust. But to be honest if filter maintended and checked periodically those parts will not make very significant change.
When it comes to exhaust its more decorative than being technical. It will give better look and better sound and will improve performance slightly but when compared to their price its abit "too much too little"
Changing the program of ECU will definetely increase power but that will also increase generated heat and will burn more fuel . In long run it will cost more as fuel consumption and early part replacements. In this aspect it becomes abit of personal choice. Some likes to live like a candle burning slightly for long time some likes to live like flying rocket bursting in gorgerous flames in seconds . So it will be upto how you like to ride your bike.
I hope this will be helpful to you. my cbr has did chain esjot sprocket performance air filter battlax tires novsight headlamps. max speed 180km revlimiter. fuel consumption for riding 360km in 2.2hour (140-180kmh speed) 3.9 liter per 100km
i clean my chain almost every 2 week and i change oil and filter aprox every 3000 km . good maintaned bike will give good performance.