Popa, I don’t know that you are correct. Just as yelling at someone is not a bad middah, so too, anger per se is not a bad middah either. I very much doubt that there are any bad or good middos; just good and bad uses of normative human character traits.
You say the person who angers easily should work on becoming engry less often. But there are of course situations where it is proper to become easily impassioned and angry. In such situations, being slow to anger might be undesirable. Jealousy too is appropriate in some situations and inappropriate in others.
The bottom line: learn to act appropriately in every situation. Control your natural tendencies when proper; let them loose when appropriate; and even develop the use of ordinarily base character traits in circumstances that warrant them.
In the learning context: Understand your chavrusa’s needs and sensibilities; be aware of your own position; keep in mind the physical setting, the topic of discussion, and the point your trying to make.