Yes, I do believe that Trump could be President even though there have been 2 instances where he walked out during an interview. It is not uncommon to hear of someone walking out of an interview if they feel the interviewer is being unfair or trying to move the interview in an unflattering way. With the way the media has treated Trump through-out this election, I am not surprised at all. Walking out during an interview has no impact what so ever on someones ability to act was President.
Trump's anger at journalists questioning him over dubious claims, scandals and faults in his proposed policies indicates a man who cannot stand up in the face of intense public scrutiny. If he is not able to handle criticism and hold himself accountable during the campaign season then it leaves a question as to how he will behave if he is ever allowed in power.
No, it doesn't seem an individual can be an effective President if they are unable to complete an interview without walking out. A President needs to be able to inspire confidence both at home an abroad. They do this by expressing themselves with authority and grace under pressure. This reassures everyone that he or she is in control.
Trump does not have the skill set to handle the office of president. Walking out on two interviews is just one example of how he is not equipped to handle the stress and demands of the position. He doesn't have the right type of experience or the personal traits needed to effectively serve as president.