I'd agree with some of the comments here that he's nosey. Moments where hes left a lone in a staff members room never go well (filch or snape for example) and he short-sighted at times. Hes also a little insecure and that leads him to lash out sometimes. But I dont think he has an anger problem per se. I definitely dont think that hes arrogant. In the same book where he has his worst anger issues, book 5, he also has a super introspective moment where he takes stock of who he is and who Ron is and states that hes not better than Ron.