I fly all of the 190's a lot, especially the A8 but they share similar tendancies.
The roll rates are the best of any aircraft in the game but are primarily, as you've discovered, a defensive asset. Use your roll rate in a defensive flat scissors to force an overshoot. You can also use a rolling scissors but will have to add rudder to create the barrel-roll effect.
Using your roll rate offensively starts defensively. At the speeds you can carry and with your rolling ability you can slam pursuers into the dirt. You can quickly roll to pull out of any situation while your pursuers can't, therefore, any time you can get a pursuer in a dive near the deck you can plant him. Bait him to get his wings out of plane with his ability to pull out, then, at the last second roll and pull up and watch him auger behind you.
In general keep 190's fast. They excel in a B'n'Z roll. They have decent turning ability for about 540 degrees of turning then it's time to extend from the fight. When you are turning do so with finesse to keep the stall buzzer from sounding.
They don't climb well or turn well once slow but they can dive like h*** (at 500 ias they will begin to shudder but you can push beyond this point without too much worry).
They seem best between 10-20K or right on the deck. Stay out of the mid-alt ranges where others can eat you up.
190's are slow to reverse. If you've got a con chasing you plan on at least 3K seperation before you reverse to him. Even at that it will be close. Do not reverse using an Immelman. Use a high or low yo-yo (preferably low) or a split S.
On a typical flight I like to come in high, dive to the deck carrying as much speed as possible, turn a couple of times for a couple of kills, then extend out and climb back to alt while I still have some speed. Rinse and repeat.
Hope that helps. Have fun. 190's are great birds.
