Sasha,
Richard is giving you good advice. Remove the AI, or the header pipes will blue. When you remove the AI, you will need to balance the carbs.
The next biggest improvement for the effort is the pipes. There are a dozen ways to improve the sound, performance, or both. You can remove the last two baffles without it getting too loud (subjective), or there are lots of subtle aftermarket pipes like TOR (Triumph Off Road)and a half dozen others that go from mild to stupid loud.
The FREAK is a great kit. Pods will require you cutting the air box or removing it completely (not recommended). You will see the most performance gains from pipes then a FREAK, as the pipes are the biggest bottleneck. Pipes are worth about 4-5 hp, then the FREAK is worth another 4-5 hp. the FREAK with stock pipes is worth 2-3hp, and requires a rejet of the carbs.
As for cleaning, I like a lot of the Meguires products, but use others, too. The Meguires quick detailer gets a lot of use in my garage on all the vehicles.
A lot of what you can/should do depends on where you live and the restrictions on modifying factory emissions.
None of this is overly complex, it just sounds intimidating at first. There are plenty of folks that can walk you step-by-step through any of it.
Welcome to the group.
By the way, if I may ask, where is home? Your English is very good, but it sounds, maybe, Russian?
