I think that the HR people will see right through those answers,
"gee, I am such a perfectionist" and "I tend to work too hard." Sounds totally canned. Try something honest. It is ok to say you made a mistake, didn't get along with someone, etc. Just be sure to tell them what you learned from it and did to correct it.
I used to be a procrastinator in college- and ended up getting a "C" on a paper because of that. I took a Franklin time management course. Now, years later, I plan out my time and schedule better because my procrastination had some bad consequences in the past, and now I work harder and I am more organized.
Once I had a terrible trip with another pilot. We didn't get along at all. But as the captain, I knew it was my job to set the tone, and try to make the cockpit more comfortable. We had some down time one day, and I offered to buy my f/o lunch. That kind of broke the ice. We ended up talking about all sorts of stuff, and then the ice melted. We were both die hard Cubs fans (yeah, I know, they suck, but hey, it's my TEAM!!) We had a great month. We became friends, and I was a guest at his wedding the following year.
Those are my examples, and I have used them in interviews. I admited I have procrastinated (who hasn't) and that I didn't get along with a co-worker (who hasn't.) But I resolved these situations. Both ended on a positive note! And both are true stories!! And don't use mine, HR people ALWAYS seem to know... and maybe I will be the one interviewing YOU.
Read Cheryl Cage's "Checklist for Success" book. Good luck.