hmmm that is a very good question. There are a couple things I really struggle with.
Impatience is probably a good one. I tend to like to make really fast decisions and they are often rash ones as well. I get very frustrated when people cant come to a conclusion, and especially with decisions that are stressful, I tend to get more upset the more time I spend coming to a conclusion.
Speaking with my head most of the time instead of my heart also is a struggle. I often then seem overly critical, and not very friendly. I say things in such a non-feeling way sometimes that especially for my F friends this really may hurt their feelings. The extroverted thinking part of me also doesn't make me a very good listener a lot of the time, so I have been trying really hard to listen more carefully before responding.
Control. Most personality profiles talk about this, and I have to say it is something I struggle with. It frustrates me when I think people aren't doing what I consider the right thing. This isn't everything, but many things. Especially when I think someone I care about is in danger, I get so nervous because if I can't stop them I am totally out of control, which then often leads me to say things that can be hurtful, or do a ton of yelling, and then tell them that they're wrong and stupid or a bad person for doing what they did. This is something I have been trying the hardest to stop because it makes me stressed and it makes the people i love upset and it's just a horrible cycle I dont really want to be a part of anymore.
Opposed to change may be one, but I have been surrounded by P's for most of my life and so they have really taught me to take more risks.
I like that you want to learn so you can grow as a person. That is exactly what learning all this stuff did for me. It's so amazing.