Buddhism and self-improvement

how does Buddhism reconcile the teachings of dropping the ego with having goals to improve ones flaws?

Very simple, it takes them as subsequent levels! Flaws are positioned as something that gets in the way of your happiness -- makes sense to get rid of them, right? Then you realize that your desire to get rid of flaws is your last remaining obstacle to happiness, you get rid of that and voila, you are done ;)

A lot of Zen teaching is for that last phase. A lot of Theravada teaching is for the initial phases. And then there are many levels of Mahayana in between the two.

This is easily reconciled by understanding that our flaws are all based on our desires. Enlightenment doesn't actually come through desire (though in early stages it may be wrongly pursued in such a way), it comes from the renunciation of desires, which, if you think about it, doesn't take desire to do away with. All it takes is wisdom.

paññāya parisujjhati

Through wisdom one is purified.

-- Sn 10

In other words, the simple abandoning of desire (including desire for self-improvement), through simply seeing desire as a cause for suffering, can be understood as the path to enlightenment.

Note, that enlightened beings do often appear to seek out self-improvement, but this should be understood as merely functional behaviour - a natural outcome of the enlightened state, whereby one acts simply out of purity of mind, not out of desire (and so would not be upset by failure or elated by success).

Fixing your ego isn't going to bring about lasting happiness. That's the old Zen adage of polishing a stone to turn it into a mirror. No matter how hard you rub, you are still going to have a stone. From the Zen standpoint, at the core, we are already perfectly enlightened beings. Compassion and wisdom is our natural state. It makes no sense to try and improve the condition of our ego. In fact, it's that very ego and its fears, attachments, and hang ups that gets in the way of our inherent, luminous nature. The more you clear away those obstacles, and the less hold that your ego has on your mind, the more you your inner luminescence nature shines through.

The enlightened mind isn't something that can be reached by self improvement. That's a contradiction in terms. Enlightenment is something we find when our self is extinguished.

Buddhism is about enlightened self interest - to sharpen one's focus onto the important things - and not just the things that are efficient distractions for most people. So, self improvement or societal improvement is definitely not a problem with Buddhism.

If you woke me up at my deepest sleep, when I am the groggiest, I am of little use to anyone, until I wake up fully. Similarly, to be of use to anyone, whether ourselves or others in our lives, or the world at large, we must first be awakened to reality of life. Or we compound errors, like someone who's just woken up, and can't open his eyes too well.

Take the case of a professional, say a doctor. A junior doctor will likely lose sleep over a mishap, like the loss of a patient, she will agonize over what went wrong, what could have been done to save him, and so on. Whereas, a senior doctor would know nothing more could have been done, and goes about life after a moment's reflection. Nothing surprises the senior professional in her sphere of competence.

It may be a whole another story outside their sphere of competence - if the senior doctor lost a lot of money on the stock market, she may react like a child, crying over it, while the senior banker shuffles off home equanimously after a similar loss because this loss and gain happens to him every day.

Life happens to all of us everyday but we cry like little children at life's agonies, and squeal at life's pleasures. We aren't very mature about life.

An enlightened Buddhist looks at all life like a senior professional. With maturity. If something needs doing it is done, if something remains undone despite doing everything, there is no panic, it is just life.

We are in no hurry to arrive, we are in no reluctance to depart.

Buddhism isn't only about denial of the self. That would be an extreme view. Just like belief in a self is an extreme view. Initially when people are unenlightened they can't even conceptualize the idea of a world without a self. At the next stage of awakening, they come to terms with the world that is empty of the self. At the next stage they come to terms with the world where a self is and isn't. They have successfully let go of either extreme.

At this final stage they are neither obsessed about lack of self improvement, nor are they lazing about without self improvement. They have developed a capacity to accept things for what they are, and react suitably. This doesn't mean they let life happen to them like an immobile rock, nor are they supermen who dodge everything life throws at them.

They are in one word - very mature. Like a consummate master of life who has seen it all, stepping out of the way of problems that can be avoided, and accepting what cannot be avoided as necessary.