Basic loops and rolls are well within the capabilities of the Tower Trainer airframe. Flying regular (horizontal) "figure eights" is a good exercise, as well. Once you're comfortable with these manuevers, you can practice a few of the fancier turns like the basic wing-over (sometimes called a stall turn) or the Immelmann turn. The "Split S" turn can also be done, but be sure to practice it from very high altitudes at first. It can be a little scary with planes that don't have a lot of elevator authority.

Once you've gotten comfortable with all of these manuevers, you can try practicing the "Cuban Eight" and getting comfortable simply flying around while inverted. How well your plane flies inverted will depend on the angle of dihedral, however. If your angle of dihedral is shallow, the plane will fly OK inverted, but more dihedral will make it difficult to fly inverted for any length of time.

Once you can fly complete ovals around the field while inverted, and even fly inverted figure eights, then you'll be ready to really tear up the sky with your Kaos .40 ARF and fly it with confidence. Advanced pattern or freestyle aerobatics are flown with the plane inverted a great deal of the time. Getting comfortable with flying your plane upside down is a big step with regard to advancing as an RC pilot.

I just finished building a Tower Trainer .40 MkII ARF for myself. I have several sport planes, but I still enjoy taking my trainer out to the field and concentrating on the fundamentals.